Don't get me wrong, it's entirely inappropriate for an American government agency to be subverting the security of American products made by American companies and used by the American public. We have a unique opportunity that no other country has to coordinate our secret intelligence work with the private sector to completely own the security industry, but we allow our government to take an adversarial approach to defense. It's insane and criminal, but that's how it is.
Imagine how effective an intelligence campaign would be against, say, Iran, if the NSA went to Microsoft, disclosed a vuln, and then told them to patch the vuln ONLY in specific markets. Roll out the patch to American companies first, but leave select targets still vulnerable. No other country could get Microsoft to do that except the United States... And we waste that opportunity by trying to lone-wolf everything.