This discussion really resonates with me. It seems that stackoverflow incentivizes very bad moderation: shutting down on-topic questions and good answers, locking questions prematurely, etc.. I'm not sure what causes bad answers to be voted to the top, but that seems like a common problem as well. And as commenters have noted, it is almost pointless for a newcomer to try to contribute.
These issues look very hard to fix, so I wish them luck. For now, I've given up on stackoverflow.
