Eh, the connection is tenuous. Sure ai becomes biased by the users who use it the most, but then you really still have to stop and all yourself: why is it we are taking about conspiracy videos instead of how people spend millions of hours watching cat videos, or memes?
There is a lot to say about the topic, but the answer really boils down to the fact the recommender systems are just good at working with variables it has access to. I don't know of any AI that has access to: "this person murdered someone" as an input. So literally, how should an AI be expected to optimize against that?
Manually tweaking the AI based on things in the real world makes sense, I'd just wish the author didn't have have it and mention Tay which is not really the same issue at all. Tay is an instance of deliberate manipulation, but YouTube is a case of wrong incentives.