[Rury]

Generally speaking, it's just how networking/reputation works.

Talent goes somewhere -> successful things happen there -> reputation is spread -> some of that success gets associated with the place -> which attracts more talent there. Like a self-feeding loop.

Happens to pretty much every social organization - neighborhoods even. Just look at top tech companies. They attract a lot of talented tech people just because in the past talented people made those companies very successful. Conversely, if they were failures, not many people would be attracted to go there...

Anyhow, that's not to say networks can decline (as reputation also attracts less talented people). Obviously careers often span longer than sports team dynasties so it might take longer to see shuffles happen in school rankings.