I had a couple of amazing instructors, in the good and bad sense of the word.
Bad one started off my FAM-1 T-34 brief by telling me, "I've got six months left in the Navy, and I'm not going to let you kill me." Things only went downhill from there, and the debrief ended with, "If this had been your check ride, I would have downed you." Well...no shit, dude, it's a farking FAM-1. As in, Ensign Fester has never, ever flown a plane in his life before today.
Good one started a brief with, "I'm going to teach you how to be a guy I'd want to fly with. The government is paying us to go fuck around in an airplane for two hours, so we're going to have fun, dammit. What's been giving you trouble so far, and what do you feel like you've got a handle on?"
I never understood the IP's who seemed determined to scare/intimidate the student. As mentioned, those guys are bullies. It's a shitty way to teach, and it's shitty just from a CRM standpoint. A scared kid isn't going to learn anything - so you, the instructor, have failed at your job - and he's also not going to say anything when something's wrong.
Good instructors figured out what you were having difficulty with, and worked with you until the problem was identified and fixed, whatever and however long it took (yes, within reason and assuming the problem wasn't just the stud didn't bother studying his procedures). Shitty instructors either defaulted to a position of "you suck, and I'm going to identify how it's your fault that you suck," or were just too lazy to instruct and went with a 'sit back and grade' attitude.
I was always amazed how few instructors understood that they were fundamentally teachers, not evaluators.