In my experience in academia, it isn’t a myth at all. So much brilliant scholarship in my own field has been produced by people who are infamously ornery and prickly, and who don’t fit in with the departments they are at purely due to social reasons, not scholarly ones. It’s actually a problem that the modern tenure and grant system requires people to be very socially functioning and schmoozing.
oh yeah, it happens so much in college because college students aren't and usually can't be "interviewed" face to face. your submission is a combination of GPA, national test score, a very short essay (that may or may not be written by you), and whatever other clubs/accomplishments on the side you can convince the admissions office is noteworthy. Perfect environment for the brilliant jerk.
I'd say half get filtered out somehow from the work force (be it in interviews or because they choose to focus on Acedemia) but a lot will still get through given the bar of a graduate junior.
