Typical response when anyone responds to criticism is "so I can't criticise him then?".
You can criticise as much as you want, however you might want to see a bigger sample size before he's consigned to the 'not good enough' pile.
For what it's worth I don't think he's been anywhere near where we need him to be, except for the Chelsea game and the assist v Man Utd. However I'm not going to say he's not good enough because the vast majority of situations he has come into haven't been conducive to good attacking play. I can't even say that he'll come good but I'm going to see if he does before I say "he's shit".