The OP might have meant less "disenfranchised" and more "people with money, jobs, and the means to move." I, for example, wasn't exactly disenfranchised when I moved to SF (poor, broke, sure, but with enough credit to get a loan and float on credit cards until I got a job).

For me, I chose SF because I was confident I could learn to program and then get a job here, and having an in to cheap housing for Chinese immigrants I knew I could do it without completely bankrupting myself. Opportunities like that don't necessarily exist in Madison, WI, as local culture makes the place a bit more traditional and resistant to, say, bootcamp-educated programmers.