I can see this if you are using the $15 plan, but there is no way they should be able to force a data plan on you. If the phone is SIM swappable, you don't necessarily have to use it all the time. What if I am only using the iPhone on longer trips to consolidate needing a iPod and phone, but during the normal work week on a short 1 mile commute, I only use a dumbphone since I have access to internet at home and work (4-6 days a month)? If you don't use any data, you shouldn't be forced to pay for it.
I have read posts somewhere (maybe this forum) that said Apple is getting a kickback from AT&T on the 3G, but didn't on the 2G?? I don't know if that is correct or not, but if it is, then maybe that is the reason the data plan is forced on you since they have to give a portion back to Apple even if you had the option to not use the data plan. That screams anti-trust in my opinion, as do all the exclusivity contracts of phones with specified carriers.
I have read posts somewhere (maybe this forum) that said Apple is getting a kickback from AT&T on the 3G, but didn't on the 2G?? I don't know if that is correct or not, but if it is, then maybe that is the reason the data plan is forced on you since they have to give a portion back to Apple even if you had the option to not use the data plan. That screams anti-trust in my opinion, as do all the exclusivity contracts of phones with specified carriers.