It does apply to all of human decision making, which is why we have different political parties, different schools of thought within a scientific field, different types of government etc. My point is that full disclosure vs. secrecy (and various points inbetween) is an instance of that type of dilemma, so that only a closed-minded person would insist their particular choice is
the only position that is always right.
As an example of how "responsible disclosure" can fail, read https://en.wikipedia.org/wiki/Shellshock_(software_bug) . It was embargoed until a patch was ready, but the patch itself invited exploitation attempts and further scrutiny which revealed additional vulnerabilities. It was quite a mess, but IMO the only "best practices"-based way to avoid it would have been to never have introduced the vulnerability in the first place. Elsewhere in this thread, I cited an instance of Apple taking three years to fix a vulnerability responsibly disclosed. Would you say it was better to let that vulnerability sit for three years than to disclose it immediately so that it would get fixed within a few months? Obviously none of this proves we should jump to instant full disclosure, I just mean the existing approaches all have issues, so there is room for personal opinion and judgment. I don't even feel strongly about second-guessing this particular instance, because I'm betting the discloser knows more than we do. (And if you don't trust him, refer to my previous comments -- why trust Apple, when they have a record of being fairly slow?)
If I'm obfuscating by saying we can't know, you're making it deceptively simple by claiming you do know with broad statements like "the number of people who can protect themselves is miniscule compared to the number of people made vulnerable" (even though I've argued third parties can help secure unknowledgable users, if the issue is publicly disclosed before an Apple patch), "It's a matter of statistics", "the fact that the vulnerability wasn't publicly known" (how do you define "public" in a way that is both meaningful to your position and can be exhaustively searched to prove the "fact" that this wasn't known?).