You do realize why this happened to AT&T and why it's now happening to Verizon, and why it will happen to the other carriers eventually, iPhone or not. With so many new smart phones, most immediately was the iPhone for Verizon, their network isn't large enough to handle all the data traffic. To curb that use, they are trying to limit the ability to tether.
If AT&T's move upsets enough people, they'll go to Sprint, and then Sprint will deal with the same problem and add limits as well.
If AT&T's move upsets enough people, they'll go to Sprint, and then Sprint will deal with the same problem and add limits as well.