Said it once, and I'll say it again. CDMA is a dead end, the world is moving to LTE. Why would anyone waste their resources on a technology with such a limited lifespan. Globally there are significantly more GSM networks than CDMA, and GSM is a natural transition to LTE. Until Verizon supports LTE (which won't be all that long), you won't see the iPhone there. Period.
Sure, they could have opened up to more carriers in the US, like T-Mobile. But look, I'm sure AT&T offered them gobs of money to be exclusive. And yeah, AT&T's network has been, well, terrible, but did that stop everyone from upgrading to the iPhone 3G when it came out?
I've been thinking about this article since I read it yesterday, and I think AT&T just screwed up their pricing model. Maybe their estimates were completely off on what they thought people would use for data. Maybe it is partially Apple's fault because they dictated some pricing terms (I do not have any idea). But if you look at simple economics, AT&T vastly misjudged the demand for data on their network versus the supply. It is understandable, previous smartphones couldn't do as much as easily or eloquently. AT&T should have charged more for an unlimited plan, and tiered pricing for capped services. As it is, they're leaving money on the table that could have been used to truly upgrade their networks. Is AT&T's cell plan cheap, not really, but would that have stopped people? Sure, there's an upper bound, but I believe AT&T's pricing is well below that.