Probably a selection bias. He doesn't want the types frequently found on Wall Street firms. He found good people who do NOT want to go there, and assume every good people does not want to go there. Or the kind of programmers he's looking for.

I kinda have this prejudice too. If you're doing Wall Street job, it's probably some boring stuff, 100% focused on money and enterprise, with crappy UI and thousands of slices of the same dozen reports.