Socially awkward can mean a lot of things. Those sci-fi guys may have different preferences, but might also have humor that strange, speak in Klingon or would appear incredibly shy/timid in front of you. Regardless they have friends because of being genuine and/or not having an agenda with their friends.
Again the only people who are without friends are those who are insincere or have an agenda (how can I get this from person X)? People catch on easily and these types of people can’t make those true bonds.