It was just people yelling at each other. There were some good jokes, and some good episodes. But after I realized that they're all just bitching all the time, it lost all appeal. I can't watch anyone on the show and say that they're a sympathetic character, yet they're presented as being sympathetic.
OTOH, the characters on "It's Always Sunny" tend to yell at each other a lot, and make all the wrong decisions, but they're losers that don't hold real jobs and have a business that doesn't do any business. It's a "realistic" Seinfeld - those characters should have been living in the slums hanging out with people from under the bridge, dragging down anyone who dares getting close to them, like the priest-turned-bum or the recovering alcoholic waitress.