Whenever I see this topic come up, I think back to the climactic speech in the movie Good Will Hunting, the one where Chuckie excoriates Will for wanting to put down roots in the community he grew up in. He concludes:

"It'd be an insult to us if you're still here in 20 years. Hangin' around here is a fuckin' waste of your time."

This was framed as an inspirational moment that finally pushed Will to achieve his potential. This idea -- that self-actualization requires abandoning your small-town roots -- is ingrained in our cultural DNA.