Coaching conundrum

This morning I was coaching at the salle and on several occasions pointed out some faults to be greeted with the cheerful response of "Oh yeah, I always do that!" This is gently amusing as a coach (although sometimes the amusement wears thin...) as I never really understand why if someone knows they're doing something wrong they just cheerfully accept it. In my book it would be much more fun to try and correct the error and get it right next time. I guess it's easier to be satisfied with the status quo but to be cheerfully accepting of it strikes me as just plain daft! Sometimes I have encountered students who have the most complex reasons for their poor techniques. "Oh yes, but I thought if I did it that way the opponent would be confused" or "Yes, I've got a bit of a dodgy ankle at the moment" etc. It's almost like the brain doesn't like being confused. Weird huh?!?
The only thing a coach can do in those situations is observe for a repetition and then patiently explain that if improvement is to occur changes must be made. After that, it's up to the fencer!