What gives you the impression that NSA is not under harsh review?

There have been many instances reported publicly about US tech falling into enemy hands. I've included a few from recent memory. This is something that happens, and I share your concern. It is a bad thing that happens, among many bad things that happen in war.

But to optimize away from it, would be to sacrifice the technological edge that keeps Americans safe.

https://en.wikipedia.org/wiki/Iran–U.S._RQ-170_incident https://www.theguardian.com/world/2015/jun/01/isis-captured-... https://www.theguardian.com/world/2011/aug/15/us-helicopter-...