I think people are just scared at everything that could go wrong.
But in reality, does EVERYTHING go wrong? Not really.
My best friend has an 02 F250 with a 7.3 with 350,000 miles on it. He's had it since new and it's been a great truck. I think he had the transmission rebuilt(4R100) in the 100,000 mile range, but i'm not sure. Other than that, just a few minor things like any other vehicle, such as a water pump or two, etc. It's got a whirring noise in the drivetrain somewhere. He thinks it may be the transmission, but when I ride in it, it sounds like it is further back than that. He has all new u-joints. Do the transfer cases make whirring noises when they go bad?