I don't think players in midfield or out wide in attack have to score or assist to prove they're useful. But it just so happens that he has been missing many crucial chances along with Giroud. The next question is whether he brings some sort of chaotic effect that allows us to create chances. Maybe. But ultimately my disgust is based on the fact that he clearly just doesn't have any balls. I don't mean he can't do a Van Persie and win you a game - none of our players can be counted on to do that. But, at least, you have to be confident a forward is likely to take a chance in crucial situations. In tense situations, he just turns into a wreck.
Wenger has given up on him. If we can find a buyer we will sell, but it's difficult to imagine anyone outside Europe will be willing to pay the sort of wages our average (I don't mean average as in mediocre, I mean 'normal') players must receive on our wage bill. Newcastle were willing to take a punt but I think the premier league must be just as underwhelmed as we are.