Judd - unfortunately, it's 'the nature of the beast'. It is not just a feature of pilot training, any training environment will have its share of such people. The common factor is, essentially, 'one-upmanship' ... "I have the power to make life difficult for you!"
When I stopped flying, I tried re-employment in Air Traffic Control. The course was in 3 phases, Ground, Simulator and Practical. The first and last were excellent, instructors and activity. The simulator was a different world with the emphasis on intentional overload. It was, obviously, a total disincentive and lead to my having a stand-up row with the instructor and walking out. Not particularly proud of my reactions but the process was a complete waste of time. ( I was classed as a 'fail', and immediately offered a recourse - as directed by the AOC - which I refused) The RAF, in the 60s, recognised the problem, which was common, and Central Flying School instructors were required to complete a Ground Instructional Training course in which the emphasis was firmly on instructors providing maximum encouragement rather than criticism. Fully accepted by most of us but firmly ignored by those who felt that their 'power-base' was being undermined. Human nature is most resistant to change.