I think there's some degree of truth to it. Speaking from personal experience, I know that I tend to gravitate towards characters who are damn weirdos/social outcasts, because I too am basically a damn weirdo/social outcast. Although their personalities, morals, etc. are all over the place.

but i also don't think that it's necessarily something to judge people for. Someone who plays only protags might want the attention because they never got it in their own life or something.

ime, people who are jerks can pick up any character and turn them into a jerk.