Yes, my gut is telling me the same thing too. The junior dev needs to be motivated (out of the box motivated) to learn and improve. If that isn't there, no amount of coaching/pair programming will help.

It's depressing. Sometimes it's not the lack of mentorship but the lack of motivation on the part of the student. It's almost like someone stuffing a gold coin in one's pocket and that person refusing to take it because it's too far or he can't be bothered.