I don't know how much they make, but it is a lot more than the users, take into account they also get the curation reward. I know you are looking for a solution, it's just that a solution in this case is very difficult because these bots have never had a good return and yet people in spite of the fact that they lose money when they use them continue doing so.
Thanks for taking the time to explain whats going on hopefully a few people will notice this post and pass it along to the dev's I know alot of people in here agree on some things and have great ideas too, cheers :)