Look, who cares if he's a better striker than Messi? the only thing that matters is, what Conte thinks of him and all evidence indicate that he doesn't rate Quag. So he is the 5th striker at Conte's Juve whether you like it or not, if you think otherwise then you're delusional.
So what were the options for this kind of side-lined striker? Money (Qatari club) or some small club (where he'd get all the playing time he wants to prove his exceptional qualities, while earning a decent wage, like Sunderland), he refused both.
He should've gone when he had the chance but he didn't, instead opted to just sit on the bench watching CL/most of serie A games from there. The only reasons I can think of for this, is that either he is a leech a la Iaquinta, likes where he is at and doesn't really care for playing time anymore,
or has a sever case of grandeur delusion and is hoping that by some outstretched miracles (like Llorente flopping and other strikers getting injured) he goes back to the starting line up (where he never really was part of, under Conte by the way), and prove to the world what a great and magnificent player he is.
It seems to me that his fanboys are rooting for the same here too, which is a pitty.
Anyways, good luck to you and your Qboy with that.