I would like to see this idea fleshed out. As I currently understand it, there is no way to prohibit bots (because of the open API). "people putting real subjective thought into how they vote" is extremely ill defined and if it were to work in any way like the Steem we have, it would need to be worked into the game theory.

I think if manual curators are less predictable then the bots will have a harder time chasing the rewards.

The problem is that we as people are pretty predictable. I know there are a few amazing AI bots out there, like @biophil 's is supposed to be, that do not just chase whales.

In my view, we need to offer alternative bots that are not purely interested in rewards, at least as an option. That was one of my goals with my own bot 🙂