People think of him as some beefed up Casemiro or something. The guy is slow, poor on the ball(for Barca standards) and not the physical powerhouse that some think he is.
I also see this perennial excuse about him being free and not that much of a gamble. Yes, but we had free players, players on which we didn't lose anything or players on which we made a profit in the past. But all those players didn't get us anywhere sporting wise. In fact that type of recruitment has gotten us where we at right now.
It's easier to just brush away this kind of signings when you have a world class midfield - see Alex Song. Harder to accept when we need signings to bring something extra, to lift the squad.