"Personally, I don't understand why people who have skills that are marketable in virtually any city in the first world"

Because, in reality, there are only a handful of decent cities that offer a plethora of jobs, interesting ones at that. Sure, a bunch of techies could move to Columbus, but there you have worse weather, more sprawl, fewer job options, and for those who do want to start their own company, a dearth of VC money.

Get YCombinator to open branches in the midwest, and you'll start to see that change. Until then, it likely won't.