Yeah, one's floating in magma- and none of the others are in places they would be exposed to a direct nuclear blast in the event of nuclear holocaust, either.
And even if they were... the reason the fang and sword (and Fiendfyre) worked is because the criterion for destroying a Horcrux is "damaged beyond magical repair". Basilisk venom and cursed fire both have a distinctly magical quality of "no takebacks". Who knows of being reduced to constituent atoms by mundane means counts? (Probably it does, but it isn't certain.)
But I assume it bothers him because if he wanted humanity eradicated, he could have accomplished it by now. And he didn't seem to take any pleasure in his belief that
"Those fool Muggles will kill us all someday!" Professor Quirrell's voice had grown louder. "They will end it! End all of it!"
[...]
"Yes, nuclear weapons!" Professor Quirrell was almost shouting now. "Even He-Who-Must-Not-Be-Named never used those, perhaps because he didn't want to rule over a heap of ash! They never should have been made! And it will only get worse with time! [...] The eager little fools who discovered the secret of nuclear weapons didn't keep it to themselves, they told their fool politicians and now we must live under the constant threat of annihilation!"
Who knows of being reduced to constituent atoms by mundane means counts? (Probably it does, but it isn't certain.)
It still doesn't make it certain to work for such a case in particular, but Snape's "From the rumors I have heard, Headmaster, Muggle weapons are only slightly worse than the more... recondite aspects of wizardry" seems to be evidence towards counting.
Edit: New thread posted here.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 86. The previous thread has long passed 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: