Oh, don't let it get you down. People do not laugh as much in small crowds. I went last night, solo, only to have a friend and her husband randomly show up. Until she came, I was all alone in the theatre. (It was a late showing on a Monday, so, not surprised.) Her husband was obviously reluctant to be there, but it was her turn to pick. She laughed a lot, and he seemed completely restless. Right up until Man or Muppet (how can anyone resist that song?!) I was convinced he hated it He seemed to enjoy Man or Muppet, and everything... and then, my friend and I got a hilarious surprise, as at the very end of the movie, he was wiping all kinds of tears away. It was fantastic. She said he's never done that ever. She's never seen him cry at all.
I love the way this movie can get to non-muppet people. I haven't met anyone yet who's seen it and didn't love it, and that includes my non-muppet friends.