Yep, he's purely a finisher. I say this all the time, in every thread... But how good was Billy Sharp's all round game at 22? Just for example. He worked hard on it in his "last spell" with us.
But also, as many have said, he needs to play off another striker probably. Makes runs and can finish. That's all he is - but with the potential to do it well at this level if supplied, as he's shown in glimpses elsewhere.
Yes he's been bad, but he needs to feel love from his own fans if we want him to do any better - even in a new system that suits him.