Heck, if Microsoft wants to control its HD content and require Xbox users to use their LIVE services rather than go Blu-ray, then I can't blame Apple for wanting iTune users to require their consumers to purchase their premium prices "i___" devices.
Myself, vendors who want to lock me down into their systems usually cause me to turn alternatives. However, some essential services have to be bought (I do need a phone to communicate with various people, so I opt to get locked in by Verizon Wireless).
In the end, if you keep your entire library with iTunes, then remember this phrase: caveat emptor.