Part of the NSA's job is signals intelligence, so they specifically find the vulnerabilities as a means of access. And if that were not the case, they would not have spent the time finding the vulnerabilities, so those 0-days would still exist and be potential attack vectors regardless.

That seems intentionally dishonest, no? If I disagree with a position I'm not justified in intentionally misrepresenting it because I feel morally correct. Unless you're alleging that these vulnerabilities were intentionally placed there, I don't understand why you'd feel the need to say that. Worrying about the effects of stockpiling vulnerabilities seems like a defensible position in and of itself.