Not surprising if you think about it. Women have to be covered from head to toe under Islam. Hair cannot be shown, so what is the point of hairdressers for women? Men do not have to keep their hair covered. Therefore, men are the only potential clients of a hairdresser. Since it is forbidden in Islam for a woman to touch a non-relative male, only men can be hairdressers.
You may not believe it, but under the burkha, those women are usually made up pretty nice -- makeup, jewelry, hair, nice dress, etc. Their view is that their beauty is only for their husband to see.
But not all Muslims do that. You'll see head-to-toe, eyes behind screens, all the way to modern Western dress. Wanna play "Spot the Muslim"?
Answer: Both.