Well first you'd need NY to collapse to prove that dynamic work locations collapse under their own weight. Young people (fresh out of school) really have few needs and so will put up with a lot for the experience of working with great people for great companies. It doesn't hurt that the weather is also fantastic (weather crushes NY but culturally NY has so much more to offer). It's only when they hit their 30's and (if they do) start thinking about children that broader quality of life issues come into play. Those that are very successful can afford to stay there. Those that aren't will move on to cheaper metros or somewhere else. Many that are successful will still realize there are other options (the realization that Tahoe never is closer than a 6 hour commute unless you leave at 4am or 10pm) and move away (making way for the next generation).

There's a reason those trains to CT are so full of people every night.