I just made a new post that expands on this idea and adds in the element that the money used to buy the votes goes straight back into the rewards pool. I think this should negate any complaint about rewards pool dilution, leaving any complaint form stakeholders lacking substance.. Unless I am missing something (which is certainly possible!).

https://steemit.com/steem/@ura-soul/a-way-to-neutralise-bid-bots-on-steemit-steem-while-still-allowing-votes-to-be-bought