Is long hair on guys "a black thing"?

This article, on first glance, strikes me as kind of stupid. If a business wants guys to have business length haircuts, whatever. But then again, it is possible that the business sees a lot of its black male applicants with long hair and has adopted the short-hair standard intentionally to screen out blacks. If so, then that's illegal. But if they simply are a public business, dealing with the public every day, is there something wrong with them wanting their employees to be clean cut?

Is long hair on guys "a black thing"? I'm serious. I didn't realize this would somehow disproportionately affect black men. Is this true?