Well actually, this is one of the many mistakes in Jenkins' work. Although many fans find themselves uncomfortable around geekfans who haunt every convention and immerse themselves too deeply in the characters they adore, the media seek out these fans with rubber pointed ears, one hundred buttons on their jackets and elaborate costumes. Why? Because TV is a visual medium, and when they send someone to cover a convention, they need to point the camera at something that will epitomize and perpetuate the popular mundane view of the media fan. That isn't the majority of attendees, wandering around in ordinary garb and tee shirts. That's visually boring, and doesn't fit the reporter or camera crew's idea of a "trekkie" or media fan. So they hunt down the guy with bottle-thick glasses and a buck teeth and a klingon head appliance and focus on him, not the visually average folks.
Whereas, I see people wearing "overly elalorate costumes" as people who are into building, acting, and being creative. It's the few people who get angry if you're wearing a Klingon costume but don't speak Klingon that worry me.