I agree with your points, aside from Steemit delegating to bots, I don't think they do

Unfortunately there are relatively few of us who see the problem this way. Any solution will have its trade offs, the idea is to minimize the costs while having an economic system that's sufficient to topple the current content indifferent form of profit maximization. That is to say, we need a new system that rewards good curation better than vote selling/self voting while still leaving enough for content creators and not shafting minnows too hard.

I truly believe a combination of slight superlinear, added downvote incentives and higher curation will do just that. No more than necessary in terms of extent.