You really do need a critical mass. I moved for my last job search and one option was for LinkedIn in Omaha. Compared to a tech hub, such a job is risky. I'm starting a family and would prefer they don't have to move more than necessary. Jobs don't always work out and living in a city with lots of tech jobs means I don't have to ever move again because of work if I don't want to. Then there's the added bonuses when a certain percentage of your community work in tech. Then the goals of your community align better with your goals for your kids, for entertainment, recreation, shopping, the environment, etc.