Despite the spectacular failures of hiring teams I don't think that recruitment process of those companies was entirely wrong. Of course there is a space for an improvement but big companies with big teams are looking for different people than small startups. A lot of people on that site did just that. They tried to go to big company and then they either went to small (at the time) startup or created their own. Their set of skill and ability to learn was perfect for inventing something new in small, agile team but was not suitable for huge, developed team where they would be just another cog in a machine.