To be fair, he's not really done anything on the pitch to change any of the doubters' minds.
It's a fair point to say that he'll almost certainly improve but anyone who wasn't impressed by him on or off the pitch before is hardly going to look at what's gone on this season and think "well he's made me look silly."
If he comes good on the pitch then he'll win people over, even the ones who think he comes across as a bit of a prat. Until then, weekly stat posts about his "key passes" aren't going to cut it.
People need to be patient. Not just the ones who are writing him off but also the ones being defensive of him. Players who have done far more for the club both past and present have taken far more shit than him. It's all to be expected.