Most have been critical about him, he's been anonymous for 90% of the time. Still, it's partially Wenger's fault spending 42m and then playing him out of position.
Just to add in, he's not played out of position in any sense of the word. a DM whose strengths are marking, tackling, strength but is weak at crossing, passing, shooting, putting him on the wing and asking him to attack is playing him out of position.
Putting Ozil in centrally or out wide, to do the same job in the same way and take up for 90% of the game the same positions is simply not being played out of position. When played out wide, something that has happened throughout his career and he himself bangs on about how good he was in the world cup... where he played out wide. He doesn't ever work the wing, he does run up the line beating players. He comes inside, stands around outside the box waiting for everyone else to do the work.
He's poor centrally and poor when he's played as the worlds most narrow wide player. I even have to give Wenger some credit here(/throws up a little bit), it looks like he's pushing him wide more recently against stronger opposition because of how awful Ozil has been centrally for so long. In the middle he's more likely to be harassed by a stronger DM or CB's who rush out than if he's a little wider and is fighting with usually less physical fullbacks/wingers.
The 42mil was a massive massive overspend on a player worth half that at best. But in some cases where you might say the price tag put too much pressure on some kid, you just have to hear what Ozil says about himself and how brilliant he is and has nothing to prove, doesn't need to improve at all. In that sense the 42mil isn't weighing on his shoulders, just purely Wenger drastically over estimating the player.
Extremely frustrating as if anyone watched 3 years of Real Madrid Ozil played like this the entire 3 years, inconsistent, strength of a 4 year old girl, didn't improve in the slightest in his time there, he stopped developing, stopped trying and wasn't nearly good enough to be worth that much.