If Wenger hadn't failed so misreably you'd be the first one piping up telling people how they were wrong and how you told us he was great, the thing is you can't because he's been pretty poor and people are calling him out.
He's not much of a manager, everyone can see that, he's been shown up for what he is now, there's no denying that, he's been called out left right and center and most people don't respect him anymore,
Moreover noone really wants him here either and he's making the fanbase turn off.