Certainly one time pricing with unlimited upgrades/support misaligns the incentives of the developer and the customer. That said, it's probably fine for a relatively low-priced product that doesn't have any particular lock-in--like a utility of some sort. Or a game. I sold a shareware program like that for quite a while and never had a problem with that model.

Clearly, there are other types of software that this doesn't make as much sense for.