What I'm particularly disturbed by is the suggestion that actions are 'tainting', that the fact that some people used nukes before somehow alters mankind from its previous state, leaving a lasting mark or stain, and especially the idea that this change is transmissible. I don't see how a child born in 2008 is somehow fundamentally different from one born in 1908 in regards to use of nuclear weapons, nor do I see any obvious way in which a society in which the WWII use of nukes had been forgotten would differ from an otherwise-identical society before the use of those weapons.

This appeals to all sorts of contamination instincts, which is why it's a common and popular implicit metaphor in various religions, but it's a very peculiar stance for a rationalist to take.