Could you not make the argument that a willingness to stay in a "doomed" city is critical for the re-emergence of desirable cities?

Almost every great city in existence has had at least one awful moment at some point in its history. If everyone took the "times are tough, I'm going to migrate to X place which is doing better" approach, then our urban geography would look so much different.

Ultimately, what gets a city out of tough times is its ability to retain the motivated people you mention. By losing those people, it seems that it's just reinforcing a winner-take-all approach to talent demographics.