It just werks 99% of the time. The few problems it brings are for the most part basically just annoyances for people used to working with something else.
That's exactly the point. It's so complex that it's impossible to track down (and thus fix) the cause of any of its problems. What works for you does not work for someone else, and vice versa, because of some seemingly unrelated difference in how their system was built or configured (usually by their distro, often even as a result of difference between upgrade-vs-fresh install).