I think it’s a case of “out of sight, out of mind”. He’s a good, solid drummer in a band that doesn’t really feature their drummer. Everyone in the band is a good musician so I think he gets lost in the shuffle. I seem to remember from a show a few years ago that they traded instruments a lot between songs, but I could be wrong about that.
But you’re right, he should be mentioned in these threads. And now he has been. I think he should let you into their next show for free. 
As for your clapping; it could be worse. I tend to amuse myself by improvising off the audience clapping. (Syncopated eighths on the two and four while the crowd is clapping quarters on the one and three, for the music geeks.) People don’t like that, for some reason. I will advise against doing that if you are ever at a performance of Blue Man Group or Stomp!