Right, but AT&T is doing LTE, just as VZW is, on different bands. Their "4G" HSPA+ rollout is much larger than their HSPA+ network, but eventually you'll probably see two pretty strong LTE networks. VZW just has a headstart.
Having the two biggest networks on the same technology is nice - someday, if they both do LTE only (and get rid of their legacy networks) then you could have a multi-band NA handset that you really could take between carriers.
AT&T not having bought any of the new spectrum makes them even harder to swallow now. They can be as anti-consumer as they want. I wonder if VZW being forced to be pro-consumer will make AT&T start to relax a bit?