Re-read that a few times and let it sink in. Pauley is essentially saying that the targets of the order have no recourse to challenge the collection of their personal data because Congress never intended for targets to ever know that they were subject to this sort of spying. And that the fact that everyone knows about it now, thanks to Edward Snowden, doesn't change the targets' ability to challenge the legality of the order.
That suggests a troubling possibility: that even if there were clear-cut evidence that the government was sending out illegal 215 orders, the people harmed by the government's illegal conduct might not have any way to stop it. Instead, the only recourse may be for the recipient of an order (such as Verizon) to challenge it in the notoriously secretive Foreign Intelligence Surveillance Court. But Verizon isn't the one whose privacy is harmed by the order, so why would it expend legal resources to fight it?
While that outcome might seem a little crazy, it's not necessarily wrong as a matter of law. The Supreme Court has ruled in some cases, including Gonzaga v. Doe, that there can be cases where, even though the government's actions may be illegal, the individuals harmed can't sue to stop them. That still leaves room for challenging the statute on constitutional grounds. But in this case, Pauley dismissed the ACLU's constitutional arguments as well.