Part of it stems from the meaning of the term, "city." While they may be incorporated as cities, three names that jumped out at me from your list are Lawrence (KS?), Santa Fe, NM, and Bend, OR, each of which has a population of < 100,000.

By comparison, Sunnyvale, CA, which feels distinctly like a suburb, has a population of close to 150,000.

One downside of moving to a small town for an opportunity is that, if that opportunity flops, it may be much harder to find the next one without having to move again. Whereas in the Bay Area, Seattle, NYC, etc., the next opportunity is likely in the office park next door, where they want you to start "yesterday"...