Roleplaying games are games. They may be many other things as well, but they are still games.
People play games to have fun.
That doesn't mean happy-laughing fun necessarily, or silly fun. It means enjoyment-fun. People can enjoy dark, angsty roleplaying games, and light silly roleplaying games, and moody tortuous roleplaying games. But they're still there to have some sort of fun, to enjoy themselves. This means that you, the players, need to take each other into account when you play.