You seem to have forgotten your own category : the ones who plays for a visual style. (I'm myself one of them)
Choosing a class on what they wear/use is not in the domain of mechanics, and neither in the domain of role/specs.
I think that in SWTOR we can add another category that doesn't exist in other MMOs : the ones who plays for an image/story.
yup, you are right, in fact second part of my first phrase was supposed to be about look not role/spec, missworded myself. Image/story is very important!