Maybe you're trolling here and I'm taking the bait, but in case you really believe what you wrote, here goes...
"The Government", carriers and the manufacture can shut them down right now. They don't because that would be terrible for a number of reasons.
Although carriers can effectively turn off your phone service, and can possibly even brick your phone if you haven't rooted it and disabled automatic OTA updates, they can't currently wipe it clean remotely. The proposed new 'service' would allow them to do that. And where there's some advertised protection against that happening, there's probably a backdoor, or at least an exploit, that can get around it.
And why shouldn't people who have not been paying there bill have their service turned off*?
Um, maybe they shouldn't be allowed to do that because they have a history of abusing their position to overcharge, automatically opting you in to services which they then charge you for, adding 'mistaken' line items that increase your bill, having really shitty dispute resolution mechanisms, etc. Not only giving carriers the ability to wipe your phone, but having customers actually sign up for and potentially pay for this 'service', further tilts the already unlevel playing field in the carriers' favour.
The media companies is a strawman or fear mongering, I can't tell which.
How is it either of these? Major content providers are on record as being in favour of, (for example), disconnecting subscribers' Internet service for even the suspicion of unauthorized copying.
"And this, ultimately, is the problem with those who keep repeating that we should just trust Bruce Schneier. It implies we should also disengage our brains."
Actually, by pointing out potential problems, asking pointed questions, and challenging the status quo, I think Bruce Schneier is encouraging us to engage our brains.