We all work for money. I love my work but I'd never work if they didn't pay me. On the other hand everyone tries to choose a career they like and everyone wants to do the work they enjoy. It only makes sense. Teaching is not so terribly well paid that someone would choose it over other jobs just for the money.
I don't blame teachers for working for money; it beats working for fresh air. As for bad teachers, I think there can also be bad learners. Also some teachers and learners will never fit together as their philosophies are too different.
@Mohammed_from_UK. It looks like you got the teacher from hell there. Yes, having lots of academic antecedents after his name did not make him a teacher. What a queer fellow!
I always felt that very important is that teachers should monitor their students' progress. His zero effort was an abysmal failure that way.
Edited for Mohammed.
Yes, I had the fortune or misfortune to have a teacher who did not teach well at all. He was my Arabic teacher in a language institute. Although he was highly qualified, he would simply sit at his desk and just talk for the whole lesson. He made zero effort to check if we understood him and none of the students asked him questions because his lectures went over our heads.
His approach was an uncommunicative approach. Finally, after droning on for an hour, at the end of the lesson, he would ask if we had any questions, which was usually met with a stone-cold silence. He'd then rise from his desk and walk out of the class.