Straight hair is boring most people have straight hair, its pretty much non descript. Its just straight, whereas curly is crazy and corkscrewy and bounes all over the place.
Allthough neither is better curly is more attractive

someone who is sexy beyond mean

Hair that is straight and not curly at all. It can be shoulder length or all the way down to your butt. Guys actually like it when a girl straightens her hair so he can runs his fingers through right before Netflix and chill or cuddling.