Reaction to the Supreme Court decision upholding an all-male draft yesterday was sharply divided. Critics denounced it as "devasting" for the cause of equal rights and lamented that it may hasten a return to the draft. Others were delighted by what feminist-nemesis Phyllis Schlafly hailed as "a tremendous victory" for anti-feminists and for military flexibility.

"We believe it is a tragedy," said Eleanor Smeal, president of the National Organization for Women. "The decision says women can be discriminated against, that there is going to be yet another exception made. . .." The all-male court is "perpetuating the myth of this country that all men are better than all women."

"This decision sends a clear signal to all women that they cannot count on achieving equal rights through the courts," said Ruth J. Hinerfld, president of the League of Women Voters.

David Landau, of the American Civil Liberties Union, called the ruling "a devastating loss for women's rights and civil rights generally." Justice William H. Rehnquist has apparently created a national security-national defense exception to constitutional guarantees, he said.

"Under the theory of the court, if Congress decided that . . . black soldiers would be very disruptive to go fight in Angola . . . Rehnquist would say 'Fine, I have to defer to Congress.'"

Judith Lichtman of the Women's Legal Defense Fund said the decision "reveals that women can't rely on the equal protection clause [of the Constitution] to vindicate the requirements of equality." However, she does not expect its impact to extend to cases of sex discrimination outside congressional war powers, she said.

The decision was no surprise and should not be viewed as a setback for the Equal Rights Amendment, several women's rights advocates said. ERA-merica, a coalition of groups supporting the Equal Rights Amendment, emphasized that the court had ruled on the powers of Congress, not on the viability of women in the military, nor on the Equal Rights Amendment.

In Philadlephia, a spokesman for the Central Committee for Conscientious Objectors, a draft-counseling organization, said the possibility that women might be drafted had been the only factor preventing the Pentagon and Congress "from moving the country to a peacetime draft" and that this ruling helps make such a move for many "politically painless."

Paul Brink, of the American Friends Service Committee, said the ruling "frees the hand of government to prosecute" the more than a quarter million young men who failed to register for the draft in the past year.

Several in Congress expressed pleasure at the show of deference to it. Among them, Sen. Sam Nunn (D-Ga.), a member of the Armed Services Committee, said, "It is now essential that President Reagan publicly commit to continue registration. . . . The uncertainty of this administration's position on continuing registration will inevitably cause a decline in the percentage of those who register."

Sen. Gary Hart (D-Col.), also a member of the Armed Services Committee, noted that Congress might still decide to include women in a draft.The ruling "will help protect families," according to a Mormon spokeswoman, Barbara Smith.

"Schlafly, an outspoken opponent of the ERA, said at her home in Alton, Ill., that she is grateful to the court for "recognizing the traditional differences between men and women that this country wants." And she added, "We've felt all along that those supporting ERA wanted to draft women. . . . There is no dispute that if ERA had been in the Constitution the court would have ruled the other way."