I think there are plenty of examples of "constructive criticism"(those saying he has struggled from the left have a point) and then there's people simply saying he was shite on saturday or is shite in general when neither of those statements are true. I can see why some feel those statements are unacceptable as a fan, although "go support another team" is a bit far.
I agree some people wont take any criticism of him which isn't healthy but some of you are being far worse on the other side of the fence giving him no credit at all so don't make out that your standards are somehow better in this. He's earned us far more points than he's lost us points, for every chance he should have buried he's provided and assist, won a penalty sometimes even been our clutch player scoring a last minute winner.