He's just far too limited, that's what leads to his inconsistency. That's where almost all of the criticism he gets comes from. Yes, he has a decent finish and he is extremely quick, but he can't do much else. If he were able to dribble, perhaps everyone would be slightly more forgiving of him. The truth is he will most likely never cut it at Arsenal. He isn't a player who can thrive playing possession football, he will really thrive in a counter-attacking set up where he can use his pace and 'ability' to kick the ball really far and run after it fast.
I'm not against playing him as a striker. Wenger is though, I feel that's why he keeps making these statements that Walcott will eventually be a striker, he wants to keep Theo happy without actually playing him there. There are still question marks over our centre forward position, so I have no problem with him getting a game or two there. Even Gervinho got a game there, so he'll probably get his chance soon enough. Perhaps in a cup game.
My opinions are all entirely based on him playing for Arsenal, so if everyone else is basing their opinions on him at England, your opinions will obviously be different to mine.