Sadly this is true. I've had conversations with very smart people who can't find a job. They often attribute it to some hiring shortcoming or bias, and sometimes that's the case. But for a couple of these people the reason was obvious: they were not "presentable" and didn't have a personality that would enable them to function well in a team, i.e. they didn't dress properly, didn't look after their personal hygiene, and were quite unpleasant to talk to.