After the fork people have some free downvotes and by some coordinated efforts they are used to downvote posts that use bidbots.

Thing is that the vote-selling kind of ruins this place. The reward was meant to reflect the quality of the post as judged by the community. That principle is very much ruined if you can buy the upvote no matter what you post.

Maybe you could simply try to go for the organic approach where you get upvotes if people like your posts.