That comparison seems weird because the relationships aren't the same. Comcast's customers are the people who pay for Comcast service at their homes and businesses. If Comcast favors its own content over other content, and they have a local monopoly on internet service, then they are using their monopoly to abuse their customers.

Neither Microsoft, nor owners of Windows Phone handsets, are customers of YouTube. The only people who are customers of YouTube are people who pay to have their videos hosted there.