"Literally nobody" -- not true, there are many users that argue for an "upvote only" system.
There are also many users who believe that the ratio between upvotes and downvotes should be high (for examples sake, say 90% upvotes 10% downvotes).
I'm not talking at all about their necessity, that's implied, my argument is that the ratio should be increased and more even for a healthier environment (for examples sake, say 75% upvotes, 25% downvotes). This can be achieved in multiple ways, as I explained above, such as removing the social barrier (UX) as well as the technical opportunity cost (downvote power separation).