alt Hacker NewsPeople have forgotten, or weren't alive, but NAT was created and deployed originally by users. The problem they were solving wasn't "how do we stop running out of addresses" but rather "how do we save money". That's because early ISPs had hit on the idea of charging more for more address space, as a way to differentiate between small and large customers. So you could buy a cheaper service with one IP and use NAT to get your whole organization online.
I was alive and don't think I've forgotten. What distinguished large from small users was the width of the pipe. Address space charging was never important as a revenue driver. There were some attempts to charge for address space to keep people from getting huge blocks they didn't use. The long term solution for that was, of course, supposed to be IPv6.
If I wanted to blame large corporate "users" for NAT (which I actually do), I would blame their obnoxious intransigent refusal to upgrade to IPv6. That part wasn't the ISPs' idea, but it had nothing to do with the cost of address space and everything to do with shortighted laziness. They were, in fact, willing to pay for IPv4 space to avoid having to do anything.