Cutting hair short “just because” and changing hairstyles frequently is a sign of fickleness, and that is inherently unattractive. That’s why short hair is often seen on little girls and little teenage hipster chicks and riotgrrl punx because they haven’t matured to be able to take care of their own appearance.
Something as simple and easy as having long, flowing, beautiful and sexy hair is a sign of integrity and being able to stick to one thing for quite a while, something that most people lack in this day and age. It’s a sign of maturity and adulthood.
There’s also something really sensual about long, untamed, naturally grown hair. Seeing it is like an instant connection to nature and earthiness and humanness, if you’re into that spiritual hippie stuff. I am, if only a little bit.
Now I’m not saying that a sexy girl can’t look sexy with short hair (because she’s already sexy regardless), but I think a woman looks like a woman when she has long hair. Long hair is a signifier of maturity and womanliness.