Honestly, I think race does play a role in this.
Since in general, outside of this forum, I and most other people I know rarely see BW with long hair, so I feel like black men might not be so inclined to consider hair length as a big deal, as opposed to the way the hair is styled, since many of us know a sistah can hook up some hair (whether or not it's healthy is another story). I think since they might not be used to BW with long hair, they might just "settle" for good-looking hair.
I say that because I have never in my life heard a BM say he prefers short hair where I'm from (and even in college and where I am now) and those few girls that did have longer-than-average hair were always getting lots of attention, even if they themselves weren't that attractive, if you get my drift. So I feel like some BM might say they don't really care about length because chances are, they haven't dated any with long hair, but I have seen more often than not that length does play a role in what they view as beautiful, or what they chase.
I don't know if what I'm trying to say makes sense, but yes, I think men in general like long hair. Like Whimsy said, you rarely see a short-haired woman being marketed to men through mags, porn, videos, TV, VS fashion shows, etc (and Halle doesn't count because people would sweat her even if she was bald).