Long haired men

I like men with long hair.

But it's something community decided is just as appropriate for men to have, as being bald is for women.
If a woman is bald, she must have cancer.
If a man has long hair, he must be an unwashed hippy playing in a crappy rockband. Or a wannabe chick.
There is no other reason.

Men used to have long hair back in the days they were "men", so who was it that decided it was anything but manly? Who decided it was for girls only? And why did people agree?
Before you know it we're going back to people saying pants is for guys, and every woman who wears pants will be called a lesbian. It makes no sense.

I will say this, though, it's really just the "concept" of men with long hair I like these days.
It feels like most men are not able to work with long hair anymore, and so I actually have to agree with the stereotype. Besides that most men with long hair I've come across indeed look unwashed and/or play in a rockband, they also tend to have a beard, and I don't dig that Jesus-image.

I don't understand it. Men never seem to do anything nice with their hair. 
They rarely have bangs, or it looks uncombed, or it looks like long fancy pubic hair. It hardly ever look like there was much effort put into it, besides them making the decision to just not cut their hair for a few weeks straight.
Is it because male hair tends to be thicker than female hair? Is that why most can't give themselves a nice hairdo?

I know we can't all be like those kawaii men in the animes, but come on now.