TELEVISION WILL not get any better next season. It's more likely that television will get worse. All indications are that only network profits and TV's population of bouncing bosoms will show appreciable increase.

As we straggle to the end of a pitiful, ratings-crazy, love-boating, peekaboo-at-the-playground network television season, this may sound like a pretty chancy prognosis. But to judge from pilots for new shows that will be on the air in the weeks ahead, and to read both between the lines and the lines themselves of network executives and producers, next fall's crop of new TV shows will make thinking men weep and smart women doze.

The question is whether the commercial network television system, as it is presently constituted, even allows for improvement in quality in any widespread, consistent, week-in and week-out way. The fact is, the pap is getting pappier and the dreck, dreckier.

To call for improved quality in network programming isn't to demand that ABC scuttle "Happy Days" so that it can air Wagner's Ring Cycle or that CBS drop "Wonder Woman" and put on Montserrat Caballe. National television programming is bound to be aimed at the widest possible audience; more and more, however, it seems widest has come to mean lowest. ABC is the network that has led the way to most new lows.

Unfortunately, what CBS and NBC have done is to use ABC's success with junk food television as an excuse for not aiming at a higher palate themselves.

Whenever you ask an NBC or a CBS programming executive why they don't do this kind of quality show of that kind of quality show any more, they always say it's because ABC supset the apple cart by becoming No. 1 and that now they can't afford any high-risk, high-style gambles; everything is too life-or-death.

When NBC did schedule a one-hour telecast of the "Nutcracker" ballet, late last year, the show turned out to be feeble-hearted as television (it was taped in the U.S.S.R.) and dubious even as a gesture on behalf of culture. NBC was just fulfilling part of an obligation the network made to entrepreneur Lothar Bock as part of its deal to secure the rights to the 1980 Moscow Olympics.

CBS also aired a "Nutcracker" - a superior Mikhail Bayshnikov production. But to be competitive, the network moved its ballet to an air-date too near NBC's and as a result, both shows wound up as lonely little petunias at the bottom of the Nielsen onion patch.

Recently the Public Broadcasting Service lucked out on a deal to televise, via tape delay, an upcoming recital in the White House by the great pianist, which is putting it rather mildly, Valdimir Horowitz. The only previous performance by Horowitz on national television was a historic Sept. 22, 1968, telecast on CBS. Yes, on CBS. In prime time. On Sunday night, the night that traditionally draws more TV viewers nationwide than any other.

In announcing the Horowitz coup, public TV officials said that commercial broadcasting had been trying to lure Horowitz back onto the air for years. This would be news to them. Fred Rappoport, director of specials for the CBS Television Network, said last week in New York that his network had made no attempt whatsoever to duplicate the Horowitz telecast and that the idea of putting Horowitz on in prime time now is unthinkable. "We could never do it; it could never happen," Rappoport said with a finality usually reserved for mad-dog TV critics.

(Horowitz did appear in prime time on CBS late last year. But it was as interviewe and phenomenon on "60 Minutes," and not as a performer.)

So how come Horowitz could take up a precious hour of especially prime CBS prime time in 1968 and not in 1978? "We were in a better competitive position then," Rappoport said. The network can't afford to put on even an hour of art any more.

Ironically or not, the Horowitz concert led off a 1968 CBS season that was still under the aegis of the slightly infamous Jim Aubrey, whose programming specialty was bucolic, rube-tube, situation comedies. The same week that Horowitz played, CBS also showed first-run episodes of "The Beverly Hillbillies," "Mayberry R.F.D.," "Green Acres," and "Gomer Pyle, U.S.M.C."

This was not the golden age we've all heard so much about. That was another decade earlier.

Even so, the week of the Horowitz telecast included a richer variety of programming than network television can claim in 1978. There were such dependable weekly muscial-comedy hours as "The Ed Sullivan Show," "The Carol Burnett Show," "The Red Skelton Hour" and "The Jackie Gleason Show" on CBS; "Rowan and Martin's Laugh-In" and "The Dean Martin Show" on NBC; and on ABC, a new, experimental weekly book-musical series called "That's Life," starring Robert Morse, and the long-running, handsomely produced "Hollywood Palace."

Walter Cronkite hosted "The 21st Century," weekly documentaries on CBS, on Sunday evenings, and, the same week as the Horowitz telecast, CBS introduced a prime-time news magazine show called "60 Minutes." It originally aired on Tuesdays at 10 p.m.

No doubt misanthropes and miscreants of the day thought 1968-69 one of the worst TV seasons ever. Were they in for a surprise! On the other hand, it is inconceivable that in 10 years anybody with a brain will look back on the 1977-78 TV season as the good old days.

And yet, next season's programs may be of a generally more mindless tenor even than this year's. Viewers will be seeing triple - or sextuple, depending on what you're counting - as the networks try to ape the success of "Charlie's Angels," the premise of which is that three girls run around, jump up and down, and model swimsuits for an hour. Tomorrow night, ABC will shamelessly imitate its own formula with "Wild and Woolly," an Aaron ("Love Boat") Spelling production which promises to feature its three Old-West bouncy-wouncy heroines cavorting in a big bathtub.

Before leaving ABC for NBC, programming chief Fred Silverman even proposed an "Angles" spin-off reportedly to be called "Charlie's Dogs." Whether or not the pooches will lounge around in lingerie is not yet known.

But it can't be a coincidence that publicity pictures for NBC's upcoming science-fiction comedy series, "Quark," feature shapely waifs of the sort that used to smile out from pre-Playboy girly mags. Nor that Robert Conrad's ever-floundering "Black Sheep Squadron" on NBC will this week add to its ranks four yummy kumquats to be known as "Pappy's Lambs." The network quotes Conrad as bragging, "Pappy's Lambs are out to make people forget about Charlie's Angels."

One doesn't want to discourage the display of heavenly bodies on television or anywhere else, but the eyeball and the brain can surely take just so much of this triple foreplay before becoming as teased-out as Charo's coiffure.

Of course, cheesecake still draws customers in other media, too. At the Newsweek building in New York this past week, there was talk that the magazine's spicy "Sex on TV" cover photo from ABC's "Three's Company" show, which featured Suzanne Somers in a more revealing pose than she ever adopts on the program itself, might make the issue a record-breaker at the newsstands. If it is, Newsweek can claim that his proves the public is upset about sex on television. That will give them an excuse to run another cover of Suzanne Somers.

CBS, meanwhile, would probably just as soon viewers forgot it was ever known as the Tiffany's of networks. Now it's the E.J. Korvette's to ABC's K-Mart. In the coming weeks CBS will be giving sample air exposure to such glittering paste from next year's program schedule as "The Return of Captain Nemo," "The Incredible Hulk," and "Spider Man." Somewhere, Jim Aubrey must be having a good gloat.

CBS Entertainment President Robert A. Daly blushed when announcing these programs to reporters and critics at the CBS press tour in Los Angeles last month. He is a grown man, after all. He also predicted that CBS could regain its No. 1 ratings position "within two years" (Calling Captain Nemo! Calling Captain Nemo! ). CBS will probably finish this season in second place among the networks - for many years it was routinely first - but no one should be feeling sorry for them. Profits for CBS Inc. in 1977 hit a new high of $182 million.

What else is in store for next year? Even the people we associate with decent, enterprising TV entertainment are talking as if they're prepared to stoop to the prevailing new low to compete. Last week in New York, Grant Tinker, head of MTM Enterprises, suggested that future MTM productions will have fewer of the humanist nuances of such character comedies as "The Mary Tyler Moore Show," and more of the cacophonous inanity of the high-riding "Happy Days" and "Laverne and Shirley."

"Our style seems to be out of style," Tinker noted. "We're just a little quiet compared with the big shows today. They're just a little noisier. Perhaps we've got to be more attention-demanding ourselves. And we will try to be."

No wonder NBC didn't lift a finger to prevent writer Dan Wakefield from leaving "James at 15," the show he created, after a row with the network censor. The program was taken over by a new team that has eliminated much of the subtlety, even to the point of replacing the low-key and beguling "James" theme with a shlock-rock ditty nearly identical to that of "What Really Happened to the Class of '65," a lemon from the Universal assembly line that follows "James" on Thursday nights.

No wonder Norman Lear is talking about manybe getting back into motion pictures again. And Lorne Michaels, wunderkind producer of NBC's "Saturday Night Live," just returned from the Coast and talks with movie studios.

On Feb. 13, in Beverly Hills, Gene F. Jankowski made his first public speech since becoming president of the CBS Broadcast Group. These speeches by network executives tend to fit the description that Hildy Barnes gave of her ex-husband in the movie "His Girl Friday": "Wonderful - in a loathsome sort of way." The speeches fall into two and only two categories - defenses of commercial broadcasting, and warnings that intervention by the government or development of new technologies could threaten the precious networks.

"The most amazing thing about television," said Jankowski, in a speech that falls into category A, "is not that it's so bad, but that it's so good.

"We at CBS believe that television programming has entered still another phase in its 30-year history. We have learned - indeed, all of us should have learned - that it is not enough to be imitative. We must be innovative."

Get together with a few TV writers out in old L.A. and you will hear just how large a load of hooey that is. Writers who saunter into executive suites with new ideas these days soon find themselves having a close encounter with the sidewalk in front of the studio.

We may have entered "still another phase," all right - a phase in which daring and enlightened risks in network programming will be entirely the province of the commercially suicidal.

Yes, TV can get worse.

Wait till next year.