I am guessing because fb is limited to private events generally and upcoming is still only really used by tech demographic (at least in London) and doesn't have

I am guessing because fb is limited to private events generally and upcoming is still only really used by tech demographic (at least in London) and doesn't have a digg/reddit like voting structure. I am also thinking he only did this idea to learn and test it out rather than as a serious business venture but then he should still have done a more unique concept since their are plenty out there....