A. You don't have to let the whole colony die if you can replace its genetic stock by requeening. Why throw those adult bees away when you can use them by combining tyhem w/ another colony, thereby boosting their population.
B. Wax moth was overcome by superior genetics? I never heard that before. Do you have something you could site which I could read too? Maybe Langstroth's colonies were werak enough from failing queens so that wax moth could prevail.
C.How long have you kept bees? Were you keeping bees when varroa went thru Indiana, killing the ferals as it did the managed colonies? What ferals came after, repopulating the cavities laid unoccupied by previous occupants, did so from managed colony's swarms. Simple as that. I guess it is entirely possible that some ferals were not killed by varroa's initial infestation of your territory, but, in my opinion, this is not all that likely.
These are my opinions and you are welcome to your own, just as I am to mine. Both can exist w/out rancor. Peacefully submitted.
p.s.: should your heart give out, should we not transplant another one into you should one come available?