I agree that data should be data and having companies pay (or otherwise sign up to be exempted) should be considered anti-competitive in such a regulated industry. But that belief won't stop me from using the exemption until the minute the FCC requires otherwise. My carrier (T-Mobile) exempts streaming music services. It doesn't charge for the exemption and any music service can sign up for it, but it's still against…
Isn't that then more of a preference and less of a principled disagreement?
I would rather have no data cap the same way my home Internet connection has no data cap. I would rather they not make exemptions for music specifically, since that shows they don't need the caps in the first place. But as long as they offer it (and I used T-Mobile long before they announced it), I will use it to my advantage.