It's just a simple case of a flock of birds who got tired of crapping in their own nests roosting elsewhere to fill it full of crap. (I think owls do this; not sure.)

What Californian transplants don't understand is how ultimately it's not even about the out-pricing of the quaint and rustic local natives. It's simply the fact that Californians move up here with their eyes aglow with blue skies, purdy trees, places to eat that don't even HAVE a corporate headquarters, and people who are more interested in bagpipes than in status and looks ... and before you know it there's nothing but parks without shade being built, strip malls full of salons of all kinds and chain restaurants opening up on every block, and everyone is either on his or her way to or out of the gym and looking like a certain Bryan Adams video.

It's the sort of clueless, selfish, and disgustingly market-driven commercial consumer culture we natives have hated all along. e.g. California.