He doesn't have to be 'world class' to be quality. While his performances are fine and people are saying he isn't 'world class' it doesn't mean he is a shite footballer and should disappear.
That whole midfield gets a 'we must re-evaluate' due to the sharp decline of Carrick, the Moyes seemingly only preferring combinations involving a shite Carrick. If we remove Michael from that midfield and try and strike up some actual functioning combinations you'll probably de-construct Tom Cleverley's game and see that there is a player with a useful amount of versatility and ability.
A system with some mobility in that midfield and he will become an important ingredient. Lets not put all our eggs in one basket and say 'he'll become world class' because he doesn't need to do that to get recognition.