I am confused as to why the author thinks it is strange of Apple to limit the iPhone to one US carrier. Apple will not allow you to run OS X on a PC, so why would they allow you to use the iPhone on any network? Historically, Apple has always limited the openness of their products. They may sell fewer units, but they ensure a better product this way.

(For the record, I wish the iPhone was also available on T-Mobile, then I wouldn't have to switch networks to get one.)