*loverly perhaps that teacher had you know... a family to get home to?
A class full of teenagers is nothing compared to parents who want to know everything. And I mean everything. *
But these issues are not unique to teaching, honestly! Many, many jobs involve managing the time spent with people to be fair to everyone, and sometimes doing extra hours to finish something, especially if you don't do the first part. You will never please every parent completely, but pleasing the most demanding one only is not the answer. If I did that at work, I'd honestly be told to manage my time more professionally.
I'm sorry if teachers find the thread negative, most teachers do a great job most of the time, and inspire many young people to be curious and enjoy studying. I know they also often work beyond school hours too. But the need to manage your time and stand up, politely, to people is common to all jobs. And many other people work in the evening, its unfortunately part of the culture in many British workplaces, not at all unique to teachers.