Advertisers want the lowest common denominator: means no monetization or recommendation for anything that might upset any part of their possible consumer base.

Advertisers want the lowest common denominator: means no monetization or recommendation for anything that might upset any part of their possible consumer base. A lot of interesting content about topics that 'trigger' different groups or that contain inflammatory opinions is thus only accessible to those who already know about it, and it's not monetized or recommended. Imagine a restaurant that starts removing anything from the menu that a customer complains about. You eventually end up with nothing but bland glop.