This:
Because bots cannot analyze, rate, or filter content by its quality.
Is factually incorrect. There's an entire Internet search and advertising industry that has emerged in the last 20 years by doing exactly that. Steem bots may not do it very well, yet, but after some development time, they will. Bots are just a continually improving approximation for their operators' own preferences.
If I ask the same question to bots, they cannot answer why the posts are good.
Their operators can.