I do not think that it is feasible to expect a government agency to solve bad engineering. There is no pixie dust that the NSA can sprinkle on systems to make them secure, even if it dedicated all of its resources to trying.
If anything, by doing what they are doing, they are exposing the fallacy of such expectations and hastening the development of systems that are actually secure. By that measure, this is actually improving security in the long term far more than attempting to bolster the status quo ever could.
It's not like vulnerabilities are rare or aren't going to be exploited if not revealed.