I agree with you that some instructors for lack of teaching skills fall back to correcting the students with mystical terms. Instead of concrete corrections, and the the reason maybe the way traditional Japanese MA are taught. The instructor demonstrates with out saying much and you have to practice untill you get it. Some people will get it physically but not understand it intellectualy. If you can't verbalize what it is then how can you teach it.
I hope this post makes sense.