Its not that they were bad professors (mainly cause I always passed my classes, so none ever truly failed me, and the separation between student/professor's fault is a thin and often blurred line), but I had one in nineth grade who said something and I immediately know the year would be bad.
Before I start the story, I should mention a small part on the way my school runs. If you finish your work, you get a teacher to sign a pass, and the students then get free run of the school as long as tehy dont disrupt other classes and show up by their next class to start. So you could leave, go get something to eat and come back and eat it, sittng in the hallway.
However if you were late and caught in the halls (or left and didnt have your pass), you got a few hours of after school (the least being 45 mins, the most being 6 hours) detention. Yeah, it sucks but it was fair when you considered that it was an incentive for students to do well.
Now this professor (yes, he was an actual professor, but claimed no college in the country wanted him), he had a habit of closing the door, and if you were late, you werent allowed in. if you went to let a student in, he wrote you up for disrupting the class, and gave you a double detention.
We also had a kid (well, more then one, but tis one was in my class that year with that teacher) who was paralyzed from the waist down.
So one day, early on in the school year, the kid in the wheel chair was late. The professor had locked the door and the kid was knocking on the door. So I raised my hand and explained the kid's situation, and most teachers gave the disabled/handicapped/physically-challenged kids a break if they where a few minutes late. The professor then said, and I quote, cause I'll never forget it:
I dont care if he's in a wheelchair, thats no excuse for tardiness. My job is to teach the students in the class when it starts. Now I have twenty-eight students here, and all of them are all healthy. I will not disrupt my schedule longer for the one broken child in this school. If he doesnt like it, then tell him to either make his legs work or get stronger and push his chair faster.
... yeah. He didnt last very long at the school.