There are lots of people for whom it probably doesn't work. It takes a certain personality, and it really helps to be a white male. Minorities are often treated differently at meetups, so I don't want to presume that my experience in a privileged position applies universally.
Fair point - and yes, it's a pity that minorities are treated differently (although it does work both ways a bit, too[1]).
I suspect those difference also apply in formal interview situations - and maybe even more difficult to overcome there. Maybe meetups have better potential to overcome negative sterotypes because people actually get to know each other a little?
Personally I think it's a pretty good solution.