One thing that people don't say is that without bidbots the great majority of the posts will not receive full rewards because they don't reach the minimum 20 steem value. I think bidbots should be allowed to help anyone to reach full reward.
How about a maximum value for an upvote? Or better, instead of blindly downvoting all the bidbots users, why don't these "paladins of the downvote" simply check the value of the bought upvote?