I've never assumed that and have been to 100's of games. I have a very good idea what the crowd is like and know that anyone that attends a game with me doesn't feel like they were "attending a funeral".
I don't care how people decide to enjoy themselves at games. Only issue I ever have is people that get up to leave or try to get back to their seats during the play, wait for a whistle.
At times I jump out of my seat and don't hold it against others that do. I do yell at the popcorn guy when he's blocking my view walking up the stairs. I do laugh at the idiots who try to start the wave in a close game and get mad when no one pays attention to them.
IMO, the crowd thing is way over blown, I'm guessing primarily by those that don't attend very often if at all.
FWIW, my seats are Purple, Row 17 where the "real fans" sit.
.....and confirms all of our thoughts.