It wouldn't really tell anyone who didn't know about Buffy who we are.
Do we need to? I mean, isn't it enough that we get it? If I were to tell someone who had never seen Firefly or had only watched it casually (as if such people even exist) that I'm a "Browncoat," they wouldn't get the reference. I mean, I didn't know about half the names on Kemy's list. It never even occurred to me that those shows have crazy obsessed fans. Surely, if Firefly fans can use "Browncoats" as their name, then Buffy fans can use something equally as specific to their shows.
As another consideration though, in the Quotable Slayer book the authors refer to Buffy fanatics as 'Buffy-Philes' so I suppose that's another one to think about, haha