So the complaint is that one day they have such a strong monopoly that they can freely turn evil?
Just want to make sure I understand the real issue here, because that sounds like a lot of fearmongering to me.
Uhhh, they have it right now, and they are currently being evil by blocking a lot of people from accessing a lot of websites.
You don't need to speculate about whether a tech company with a monopoly over a major distribution channel will extract rent from it - it's incredibly profitable to do so.