I think that's a bit of a stretch, It's down to the average stupid consumer buying devices they want and cant really afford on contract to a telco and then complaining when they dont get everything they want. I haven't bought a phone on contract since the 90's and I never ever would. Maybe there's less choice in American but that's another problem not so much Apples.
Here in Australia i bought a 3GS, unlocked from an apple store, stuck in my Vodafone 3g data sim, and it tethers fine, no jailbreaking, no client login program like the vodafone USB dongle and better reception at/around work where i use it, I dont need to find or download the vodafone install disk/files if i format/change computer.. so if anything it's better than the modem vodafone sold me, its faster and just works better.
Anyone getting excited about phone tethering now is so behind the times it isn't funny.