I dunno, I think it's a lot simpler than that: if they referenced   
   Babylon 5 all the time, most viewers wouldn't get the jokes.  More non-   
   sci-fi-buff viewers will GET the anti-Wil-Wheaton jokes, and Sheldon's   
   Spock-man-crush.  Sure, they could have made Sheldon a B5 fan instead,   
   but Sheldon getting excited over "possessing the DNA of Michael   
   O'Hare" would leave about 99.9% of their audience going, "WHO???"  For   
   the jokes to work, they have to reference something that's a near-   
   universal cultural meme.   
      
   Naturally, they need to counterpoint all that... for that they could   
   have probably chosen any number of sci-fi shows for Sheldon and the   
   others to debate over: Star Wars, Battlestar Galactica, etc.  If I   
   were to really fanwank over it, I'd consider it an honor that the   
   writers DO recognize B5, not just as a contemporary to the later Trek   
   series, but as a "worthy adversary" to the entire franchise.   
      
   Then again, I also picture JMS reading this sort of thread, standing   
   up at the front of the room, looking down at us all, and screaming,   
   "it's just a TV show dammit, IT'S JUST A TV SHOW!"   
   --- SBBSecho 2.12-Win32   
    * Origin: Time Warp of the Future BBS - Home of League 10 (1:14/400)