The virgin soil hypothesis becomes stranger the more you think about it:

1. It's wrong.
2. It is largely spread by a desire to downplay the genocide of native Americans (more complicated than this but it is a large factor)
3. Disease (syphilis) spread FROM the Americas TO Europe

I wonder if the occurrence of the black death also plays a role in its persistence. Europeans and our descendants can believe in a continent wide apocalyptic epidemic because we experienced something somewhat similar