1) He's wrong. My first job in Arizona I got paid more than that, 15 years ago.
2) It's so, so much cheaper to live in Phoenix than in one of the tech centers. And a different lifestyle. Some people want a big house and a boringly steady job.
Universities are not going to pay as well as the private sector, or even many government or non-profit organizations, for the same work. Using that as an example doesn't help your argument.