I think 90% of teachers would say it's not the actual teaching they dislike.
I am going into my 19th year-in a tough secondary school, where only about 1/10 kids have professional parents and fewer than that even dream of university. They swear too much, they don't often know boundaries or manners, their 'worlds' are narrow and, often, incredibly depressing. And do you know what? They're great! They are rough diamonds, pleased to see a welcoming face, funny, warm, entertaining. In my classroom I am as happy as I was when I was a fresh faced NQT. I laugh every day and I am honoured to work with these kids.
In the staffroom however, or more importantly in staff meetings, I want to weep every time SLT tell us we're not doing a good enough job because the targets are ever higher, or how we need to re-write the whole curriculum because of governmental changes. Throw in the ever present tick box exercises, the 3 layer data analysis, the increased duties and meetings, the constant fear of OFSTED, the marking scrutinies, the observations....
They're the things that make me- and I would guess most moaning teachers- whinge.
I thought about quitting last year but I'm not foolish enough to think that I could get an 'easier' job. The pressures on ALL working people now are higher, but I do think that the willingness to bash teachers is ridiculously high. Most of us do this job, and continue to do it, because your children are important to us and their futures might be improved by our presence.