Long hair for women, short hair for men. That's a stereotype so cemented in our society that it's almost treated like a tertriary sexual trait unless you're really buff or can show off curves.
For me it really depends. Not just on the rest of the body aside from the hair, but strangely it also depends on the hair color. I think light hair looks better when long and dark hair looks better when short.
[link] I've only encountered in fiction so far, but after the initial "wow" effect from seeing the size I'd probably think something like "That's gotta be a bitch to maintain". Definitely wouldn't obsess over it, but I'd probably be impressed.
So if very long hair scores extra points, it's because it combines a feminine stereotype with an extreme that is an achievement on its own. Not all men like long hair tho and the hair preferences, as far as I can judge, spread much further than preferences in personality or "the three sizes". If I had to analyze it, I'd probably "blame" it on the Emo and Hipster fashion trends that push out blond in favor of black, and sometimes also long hair in favor of short hair (because it's "geeky and cute"). Doesn't seem to hurt the fanbase for red hair tho. I'm inclined to say "on the other hand, real examples of women wearing hair past the hips is really rare anyway, so it's not discussed much", but that goes for pretty much any fantasy. So yeah. Apparently this obsession is nonexistent in both my area and the parts of the internet I visit.
TL;DR So I think I can close with saying long hair is desired in the same way girly girls/womenly women are. It's certainly not everyone's taste and I don't remember a wide-spread obsession over very long hair.
Though on a regular basis you will find people with their own specifics, but rather it will all mainly boil down to each person's preferences, maybe like in my case, i wouldn't really care if a lady's hair was short or long, but rather i prefer that it would suit her desires, but if i had a say, i would suggest she cover it (woo-hoo )
We men are often lazy and unfortunately..quite daft.. so we're a bit slow i'm afraid, but.. to ponder.. Short hair gives that..nah i dunnno what to call it.. but long hair.. well, i did so hear people make big ideals out of stroking it, then again.. what we talking about? women's hair or cats?
of course of course, But i did not mean it in a bad way, after all, What a lover does to his or her beloved is their own right and freedom to do so, we cannot stand in their way (unless it's something REALLY bad of course..like.. something to do with kitchen knives and monochrome shower scenes)
but as said before, to each his own preference and ability to adapt, for a woman's style of hair often tells a tale about her uniqueness, as a man's choice of lifestyle and even facial hair.
There is no right answer, the opinion of long or short hair will differentiate between every person. Personally I can't stand hair in general, and much prefer short hair on girls, but oddly enjoy long hair on guys.