Earlier quoted context omitted.
there's no downside to having this additional option available. Sure there's a lot of value in communicating with other Facebook users, but if you can't see the possible downside of having a large group of people's first and only connection being through a corporate-controlled view of the world, you're not using your imagination.
Can you actually make the argument that access to Facebook/Wikipedia/etc is worse than no Internet whatsoever?
So not only does it prevent competitor websites, but it stops competitive ISPs, too. It's especially bad if this coporate network is censoring information. No opportunity to even discover non-filtered information outside the info bubble. This triple whammy is the consequence for those involved or not.