Saying that meditating is "you just sit" is like saying that exercise is "you just move". You'll get somewhere doing only that, but not very far. Things in life that are simple, we already all do--like wiping our asses. On the other hand, meditation ends up working for some people and not others, and different people require different amounts of time and effort to get anywhere. This indicates that meditation is like any other worthwhile thing in life--not simple.