It isn't in favor of AT&T. At all. Having platform lock in means after they sell you a device they can price gouge you indefinitely and since you probably bought the device outright since you aren't on a 2 year contract and thus have the option to change carriers, you probably don't want to just ditch it immediately.
Platform lock in is good for device manufacturers, carriers, and business, but bad for consumer freedom, choice, and market competitiveness. And there is no multi-billion dollar lobby for the the latter.
It helps to know who they got money from, because if I ask them to take a stand that their donors won't like, that is where the counter argument will come from. Sometimes you can cut that off before it happens by going to the donors site(s) and looking for white papers or position statements that outline their arguments for what it is they believe.
The process is slow, but it is pretty durable. I've got both the petition and the Whitehouse response in my notebook, and we're in an 'off' year but next year we'll put a bunch of new candidates up for congress, this will come out again as a test to see if they did what was demanded or not. So the stage is set assuming we use the tools given us :-)