We have a coturnix hen who, as a young one, must've injured her neck somehow. She walks with her head turned to one side and has learnt to navigate the world in that position. I was worried initially that she wouldn't cope, but they are incredibly tough little birds.
If you don't mind the bit of extra effort your bird will need, and if it seems to be coping ok, then I don't see any reason to cull it. You could ferment his food as a thick mash texture might be easier for him to eat than crumbles perhaps?