My average flight experience has been the same across all major airlines over several thousand flights, many of which were on United. Some are late, most are on time, and sometimes shit happens. Most (probably all) of the alleged horror stories in this thread and every other thread could very easily apply to ______ instead of United. I especially like the one about landing at the departure airport due to bad landing gear because that definitely sounds like the whole story. Not. The number one priority for all airlines is to land every plane at the destination on or ahead of schedule. There is no way a plane would turn around for that kind of stupidity and if you truly believe that's the whole story then I have some beachfront property in Kansas you may want to buy.
This is just like politics; if you think your side is the best, you're just as stupid as everyone else. All airlines make mistakes and none of them give a shit about you, which I don't mind one bit. They're in business to make money just like I am and I, just like everyone else, absolutely make every optimization I can as my business matures. Airline seats used to feel like the back seat of a Cadillac, which was nice, but incredibly wasteful. Of course I'd rather have more leg room, but I'm not going to drive for 20 hours because my legs aren't able to fully extend. You are perfectly welcome to feel differently and vote with your money, but most people obviously disagree. It's like Walmart crushing the little guy - "Down with Walmart!" yell the townspeople in defense of local stores as they stuff Walmart bags in the trunks of their cars. If it truly gets bad enough, people will stop flying. Until then, airlines are going to do what every other business does - squeeze every penny out of you that they possibly can. You are not entitled to fly in airplanes for the amount you deem reasonable and if you choose to stop flying on an airline because someone else punched an asshole in the face, they will not feel that loss at all. I bought 30 tickets on United in the last two months because they were the least expensive and/or had the most convenient schedules. When I chit-chat with other business travelers, I hear the exact same opinion.