A system based approach is too much expected from the developers, I guess. At least for now, I see no way into getting them into this.

But what might be a better way is to get upvote bots to adapt their conditions. Meaning, you could force them into limiting the age of posts to maybe 36-48 hours and don't accept requests beyond 3-5$. This would take a good part of the sting out of the Steemit flesh, I believe. According to a recent post by @paulag, bots make up about 25% of the rewards on the platform. Getting that down to 10% and leaving it there would be much and I think you can do that with these time+money limitations.

Another aspect could be to force upvote bots into only accepting (or paying) SP delegations to a certain threshold. Personally, I think 100k SP should be enough - @boomerang would pay for that >150 $ per day! Everything beyond that should be cut off to make sure the majority of the money gets redistributed within the system and not dumped on the market or ending up on holding accounts.

I'm confident, my strategy would work there too. But that's something for another day;-)