I haven't fully dug into all of the options that Toyota has in this situation, but I have trouble believing that the company hasn't explored them all and is implementing the countermeasure that maximizes safety. I used to be a project manager at a Toyota manufacturing plant, so I have some experience with how decisions like these are made within the company. Don't get me wrong, the situation sucks all the way around (I have an '11 SR5 that has spent it's whole life in Zone A, so I'm right there with you), but I truly believe that they're trying to make the best decisions for everyone within a bad situation. The bottom line is, there just aren't enough inflators that can be manufactured quickly enough to go around, so they're having to prioritize the ones that pose the greatest risk.
Regarding disabling the airbag, I have attached a document that explains the company's position on this: essentially, they think the risk is higher not having an airbag than the risk of the inflator exploding:
Also, the NHTSA remedy order was just amended this month with updated dates. OP, the 2011 is in Priority Group 6, which means they now have until Sept. 30, 2017 to have the remedy (i.e., new parts) available. I have attached the FAQ that I quoted above and the amendment to the remedy order to this post for everyone's convenience.