I don't think school is ever enough. It is meant to impart some basic skills and socialisatin rather than satiate a childs capacity to learn. Good schools should make kids want to learn more,not teach them that all there is to know is in the textbooks and then they can stop
The only thing I ever argued about is when a teacher gave my kid an A for acheivement and a B for effort. If she acheive and A in the cirriculum work she should be free to spend any remaining time pursuing her interests. Saying she wasn;t trying hard enough makes no sense at all. That's the kind of thing that makes me wonder if the school is the one lacking 'gifts'.