Well, yes. Sit idly and push a few buttons, or have an actual hand in the combat system. MMO combat might as well be a playing card game. There's no mechanical skill or split second decisions, only really slow decision making.
MMO's can require skill, have you ever tried farming on Guild Wars where you go out alone and try surviving in Hard Mode? Sometimes it's extremely difficult, other times it's easy. And idc whether I have a hand in the combat system; I prefer MMO's because I can get rich with gold and show off to everybody (although I've never done this but I wish) and I can listen to music where on my xbox or whatever I dont want to/cant because I cant pay attention as well.
I hardly see games require much skill these days either.