I know he hates it but like he said himself, what can you do?
Maybe he likes it better at Juve since he doesn't have cack players like Muntari and Boateng taking his spot in CM.
"“I think I am one of the players on the pitch with the most quality and I am very useful when I help out in attack."
He's basicall saying "why do I have to play in defense when I'd wreck shit in attack and turds like Boateng and Muntari play there.", but politely.
If Poba, Vidal, Pirlo and Marchisio play there instead, I think he wouldn't really be mad. He seems like a really unselfish player to me, and I reckon he just feels that playing him in a more attacking would help the team much more. With the aforementioned players taking the CM roles, I think he'd understand.