Straight back at you mate, anyone who thinks Fellaini is a good defensive central midfielder doesn't have a clue about football. His ability to read play was crap and he couldn't track a runner to save his life. That's why the likes of Tom Cleverly were picked ahead of him at Man United, and it's why Fellaini will eventually be sold to the likes of Newcastle or West Ham for about 15 million, where he will be stuck upfront, as that is where he is effective.
I've had this discussion too many times to remember mate, those who know what they are talking about will back up what I say, those who are blinded by his boss perm will continue to describe him as the white Patrick Viera, despite the fact that he can't get a game for love nor money at Man United.
Before Neville was finished, he was good at protecting his/our defence. Unfortunately there are no statistics that relate to reading the game or tracking runners, which is a shame as it is one of the most fundamental parts of midfield play, far more important than the number of touches a player has during a game, or how much ground a player covers during a game.