A noted colleague was heard to have said bluntly but honestly, "Playing an instrument doesn't take brain surgery, just practice!!" Most issues must ultimately be solved by the student in the practice room. Granted, information, direction, and motivation are needed, but teachers cannot simply be expected to pass on a gem of amazing wisdom to immediately solve every playing problem. If a student is not willing to slug it out consistently on his or her own, then no teacher anywhere will be of any help.
There are great teachers, but there are also great students. The great student is not always the best player, but the best improver.