One of my toughest professors (inorganic chem) made me cry often. However, she never once degraded me. It was my perfectionism and struggle with the math concepts that did me in. Then the day she said she would not help me until I came back with specifics totally angered me, but I went back home looked at the material for the millionth time, determined where the exact problem was and went back to her. THEN she could help me. The woman revolutionized my studies and my education. And yet, she was rumored to be the hardest professor in the school, and called a few choice names.
She was tough. She expected you to work and to work hard. She was, however, fair. I will forever adore that woman.