Those places have trade-offs, just like anywhere else. For example, the Midwest is a very nice place to live, but the winters here are absolutely awful and we also tend to have at least a month in the summer where it's also extremely hot. The job market for tech is decent, but it's not nearly as lucrative as the coastal markets, although the low cost of living does make up for that to a degree. These things matter a lot for some people, even if not so much for you.

As much as a lot of non-SV folks, myself included, enjoy ragging on California, the nice weather and good job prospects make it a very desirable place to live, and as such makes people far more tolerant of the hilariously awful housing situation and political climate.