All you bald guys take note: for better or worse, hair matters to a lot of women. 
And you, the gay man, knows this how? I get more play now that I shave my head (because I'm really thin on top) than I did when with hair. From having flat tops, long hair, shorter styled hair in a different types of styles...shaved is the the best- easier to deal with too!
And every woman I've met, talked to-sexually or not- have all said they liked shorter hair/shaved head just as much as having any other hairstyle.
I think the underlying principle is not how long your hair is/isn't. It's what you look like with the amount of hair you have.