Downfall of Númenor -> Culpable are the Valar?

[Eonwe]

So that leads back to their creator.

Not necessarily. In the Silmarillion, Tolkien tells us that, just as the Kinslaying corrupted the elves in their very cores, so did Men listening to the lies of Melkor.

Could this is his interpretation of the 'sin nature' in Christian theology? If so, then I think that would put the blame once more back on the Numenorians themselves. After all, nobody is forceing anyone to do anything. Free will and all...