Imo the downvotes should be used exclusively for plagiarism and spamming, for me hasn't too much sense to downvote something because the content creator has too many rewards or because you don't like it.
That's a very subjetive pow that can be used for multiple purpouses many of them unjustified. Saw in the post of DAO (i think that most of us know which is) downvotes on comments because simply one user disagree with another, that's for me a bad use of downvotes that can end in a flag war or in bullying someone.
I see that pretty absurd and bad looking for newcomers, gives the sensation that this blockchain is a bit like a jungle with a darwinist pow "the survival of the fittest" that I don't like at all.
I liked your post, imo has very solid points.