When I trained in Japan in the seventies, instruction was by and large through criticism and repetition. To hear “ojouzu” (you are skillful) was the kiss of death. A truer translation is (yeah yeah you are great, go and bother someone else).
In those days if sensei liked you and cared about you, they generally gave you a hard time, with the best intentions of helping you grow under pressure. My first real kendo lesson in Osaka was with a well known, (now even better known) police sensei. It would be diplomatic not to mention his name, but he is small and exceptionally good at tsuki and kote. I was an experienced kendoka, fresh from the British team in the World Championships and ready for the next step.
Sensei enlisted the help of one of the lady police students and asked her to take me away and put me through a footwork drill. He returned half an hour later and asked me to demonstrate. When I had finished, without a word to either of us, he moved behind my mentor and gave her a hard kick in the backside and then walked out. That really set the tone for my time in Japan; I spent the next three years trying to grow from incompetent to unnoticeable.
At that time most of the Japanese learning kendo were there because they had to be, so fractured feelings were never a major consideration in kendo teaching. There was also the tradition of waiting for days outside the monastery door to seek admittance as a gopher, clearly things have moved on. Now people take up kendo from choice and instructors need to walk a line between encouragement and sufficient criticism to encourage improvement. The drop out rate from kendo is significant and potentially even more so if instructors are overly severe. The counter argument is that people who can take verbal punishment and exhausting practice are the people we need in kendo.
Fortunately we have many professional educators involved in kendo. Certainly in the UK, these specialists have tried to help those of us who do not have a formal teaching background develop as communicators. So taking their encouragement on board, I have tried to curb my natural critical approach and look for positives. This is of course easy when teaching small children, who I believe deserve nothing but praise and encouragement, but with consenting adults it is still a difficult call.
So if I tell you that your posture is great but your fumikomi is crap, chances are I like you.