I mean come on, sure 120-150k starting salary out of university is only a thing in SF, Seattle etc but even in other parts software engineers are paid well. 80-90k in some city in midwest where housing is super cheap is a great middle class salary.
How much lower is the starting pay in Boise, or Kansas City or some non-tech hub? My startup company pays well over 100k for college hires with no experience. And other companies pay more. Yes, we are in one of the tech hubs (Seattle). If other companies don't pay nearly as much, why would people work there?). You might pay 20k a year for your cool apartment in walking distance to bars, shops etc, but you have a great lifestyle.