Paying for voting does not drive up the quality of voting, as described in the post.

I'm not totally convinced of that. streemian, steemvoter, and autosteem have enabled hundreds of thousands or millions of votes that would not have been cast otherwise. That probably wouldn't have happened without the incentive that curation rewards provide, and we have no idea what the platform would have been like without them. Also, we have yet to see how things play out in the long term. Many people are still unfamiliar with the rewards rules.

I have thought that it would be interesting to see what happens if bots and guilds all shut down voluntarily at the same time for a couple of days. My guess is that a small number of authors would like it a lot and most would not. I doubt if we'd be able to coordinate that experiment, though.

And just stating the obviously (not that it is a horrible thing) but it would essentially be a form of vote buying / bribery.

Maybe. Or maybe it's just an inducement to evaluate a post that a curator might have otherwise ignored. I doubt if many people would intentionally vote on poor quality posts just for a tiny curation reward, especially knowing that it's likely to be a wasted vote because other voters won't do the same. Either way, as long as it's transparent, I don't see it as a problem. The complexity would be my bigger concern, and may well be a "show stopper."