So there are teachers at shcool and there are lecturers at University. As far as school teachers go, there are very few who don't at some level care about how successful their class is. But there are some teachers who are really good, and some who are just incompetent. I don't think everyone necessarily realises how much teachers have to be able to do to run a class effectively, so not being suited for the job isn't exactly a slight. It's also partly the curriculum's fault for being so focussed on rote learning and exam nuances rather than just understanding the subject. But I had a Chemistry teacher who practically thought rote learning was all it was possible to do and taught as such, which didn't help me much, but there was another problem - my classmates were so effective at shutting her down by constantly asking for clarification like they're stupid (they actually weren't) that we hardly ever got through the lesson. Another problem was that she just didn't know the content very well. There was one particularly tricky concept that she made very certain to define because it can be confusing otherwise, and the textbook disagreed, and I still don't know which is correct at the end of that.
I also had a Maths teacher, who, while strict, had a sense of humour and was very good at explaining things conceptually. Unfortunately for her I was just shitty at Maths, but she was a good teacher because she promoted understanding rather than rote learning, and COULD. Rote learning is an easier way to teach and is really the metric I use for seperating good and bad teachers.
Lecturers on the other hand, I had mixed experiences with. Most recently Electronics - the guy was apathetic along with all of the tutors, to the point of being condescending, had an Indian accent and a lisp and was softly spoken. I learnt hardly anything beyond which topics to look up later at home. Programming Fundamentals - the guy had a slight Indian accent but was very animated, good at explaining and thorough with the material. He is pretty much the only lecturer I've had all year that could have made his 6-8pm Friday time slot work. Mechanical Engineering - such a severe Asian accent that even Asian students I've talked to can't understand half the things he says. Not his fault at all, and the notes he provided were quite voluminous in examples, but still learnt practically nothing from what he said.
You may notice a theme with accents and point out I'm being racist. I'm not, it's a communication issue, and in Asutralia we have a lot of foreign lecturers whose accent actually interferes with education, and in 1/4 cases this semester, the lecturer doesn't care how well he is getting across information.
tl;dr - there are good and bad teachers across the board.