Here's just one partial illustration to my argument about focusing on the wrong indicators (the fairness of sharing a worthless cake called "the reward pool").
Does our discussion have value ? I reckon it has - it allows me to learn about you, to hear and think through your arguments and come up with some answers (for what they are worth). It allows you to do something similar. We both learn something.
Well, if I had not used the bidbots to reach trending, this valuable conversation would simply not have happened. We would have not generated the associated value.
The steem in the reward pool is an illusion to get people to interact with each other and produce valuable content and learn. There lays the real value, all the rest is just illusion. In that sense, the bid bots, associated to the "trneding", are a good mechanism.
That being said, taking a step back, I think ranking posts in "trending" by the payout is a really bad idea. Post quality should not be assessed by how much rewards they gather. But I can't change that. Since I have to live with it, then the real goal is to generate valuable interactions within the rules of the game.
In other words, it's not the bidbots that are bad, is the "payout means quality" implicit logic of "trending" which is the original bad idea.