It's not anticompetitive with respect to other carriers, it's anticompetitive with respect to non-Binge web services.

As a T-Mobile customer, I don't care about other non-Binge web services. I'm paying T-Mobile, not them. Meet their BingeOn guidelines, or make the value prop compelling enough for me to burn my data quota up on you. Otherwise, you're asking me to subsidize your service through my monthly rates to allow your innovation or "freedom of expression".

...and that's exactly why discriminatory deals like BingeOn should not be allowed. If Tmo wants to offer unlimited 2mbit traffic, let them offer it for all sites equally.

I'd rather not subsidize an interpretation of idealism through my mobile bills.

You've got it backward; all the other sites are subsidizing your unlimited (but site-restricted) streaming.

Here's how to do something like BingeOn right: work with IETF to define a QoS flag that indicates streaming video, allow customers to opt in to throttling of that flag, then make sure everybody knows that they don't have to coordinate with Tmobile -- any provider can use the flag, and any carrier can honor it. Finally, the carrier could put an icon in the phone status bar (or an LED on a hotspot) indicating whether the current video streams are throttled and free.

just because they don't have a majority doesn't mean its not anticompetitive.

Without a monopoly, anticompetitive behavior is going to be much more difficult to prosecute.

Rofl... this is the US, to prosecute anyone for being anticompetitive is almost impossible.