YouTube is not the ministry of truth, it is a popular entertainment website that people visit voluntarily. People very incorrectly treating YouTube like it's some kind of authoritative source of knowledge is the problem, not YouTube.
They're not doing this for marketing reasons. They're doing it because they believe by controlling YouTube they control what people think. Even if they're wrong it's dystopian and suggests a megalomanic attitude.
Remember this is the same company that controls Chrome. It's all fun and games right up until people start discovering their Chromebooks and Androids are blocking web sites on the grounds of "misinformation"
