Having been the target of one such instructor myself several years ago, I can readily empathize with the nurses and students who wrote those entries. Everyone appreciates a kind word of encouragement, especially those who are new in nursing. It costs nothing and takes so little effort, but the rewards are enormous.
Nursing is indeed a tough profession, and it's certainly never going to get any easier.
This is all the more reason for instructors and supervisors to treat those they teach or supervise with patience and understanding. Being tough doesn't mean you can't be fair and kind. You were once where we are now. When we make mistakes, correct us, but do it in a helpful and constructive manner. Don't berate us, intimidate us, or tear us down.