I reckon, having been playing with a new Linux setup on my proxy, that a big issue is how technical things can get.
For general office use, it's perfect, being quick on even bottom-end machines, but as soon as you start doing something even remotely technical on it, it has a huge learning curve. I'm sure absolutely all answers can be found online, but this stupid attitude that a lot of Linux-gurus have where they say something along the lines of: "Yes, I know the answer to your question, but I'm not going to tell you what it is. Instead, I'm going to point you to this 100 page document to read through", is absolutely frustrating.
You may still live with your parents and not have a job which allows you to spend so much time on something trivial, but a lot of people don't.