Can't speak too well for other cities, but in Hong Kong, up until very recently, no one besides hedge funds and grad schools had interesting programming problems to work on. So if you wanted to be surrounded by good hackers, you either went into finance, or you were in an M.Phil programme while you wait for a visa to go to a country where there's non-finance jobs with interesting problems to hack at.
Fortunately this is slowly changing (after years of useless government "innovation" initiatives like CyberPort which just turned into subsidies for politically-connected real-estate developers); we've got more non-finance companies doing development (and not just sales), like Artificial Life, and there's more of an entrepreneurial vibe in the air (rather than CompSci majors automatically chasing after jobs in the big companies).
Fortunately this is slowly changing (after years of useless government "innovation" initiatives like CyberPort which just turned into subsidies for politically-connected real-estate developers); we've got more non-finance companies doing development (and not just sales), like Artificial Life, and there's more of an entrepreneurial vibe in the air (rather than CompSci majors automatically chasing after jobs in the big companies).