I think it's his age that does it for me too.
If he was younger then maybe you could have hope in him developing his ability to cross higher balls into the box, but as we both know, if you don't have that at this stage then it's unlikely to improve.
I do like him as a player, he works hard, has pace, and is a bit tricky. His end product is very inconstant though so I'm starting to think maybe move him on if we can get better.