Emotional Safety in the workplace

Does it exist? I have worked for some great people in my experience. Some people become managers who are actually good managers. I had one supervisor in a temp job, someone made a mistake and had to do something all over again. She says to the person, "So, you made a mistake, you're human--now you won't do *that* again." Never raised her voice. The person's shoulders fell back into their proper place and they did the work again--twice as fast and no errors.
Meanwhile, there seems to be a lot of people out there who, after coming off as the greatest, most charming personalities, work hard to become managers and as soon as they have the power--you can't talk to them anymore. There's a problem and they are screaming, or, you make one mistake, after going along for months, years of no mistakes and you are lectured for hours about how " We just can't have that kind of work performance. One more of those and you'll be written up."
Matter of fact, if you stand in the corner on one leg and it's the wrong leg--you get written up. You sneeze, you get written up. A previously spotless record is blighted with write-ups under this new management.
Then the migraines start. The manager says as soon as you get treatment, i.e. a neck adjustment, you should be able to come back to work. Yeah, migraines just go away like that * right? Once, a recent boss I had told me that this other fellow I worked with had a migraine and he came to work, he came late and he left early, but he came. Now I had happened to talk to this fellow and I know what caused his headache. I am not a snitch, but what she was saying was unconscionable. I told her, "I'd have a 'migraine' too if I'd shared a 24 pack of beer with my friend the night before."
Her face went blank a moment, she hates being wrong. Suddenly she says, "Well he still gets migraines."
My answer, "Well, then he shouldn't drink."
So, I ask, what are your experiences. The positive ones set us a good example of good managership and we can create a 'book' so to speak. The bad serves as a warning of what people should not have to put up with in an already stressed out economy. Let's make it easier to work, not harder. Eh?