That is true. I agree with you. But his teacher

not wrong either. No one stops him from having fun but he needs to understand working is important too.
For example, my son usually use 1/3 to 1/2 of the time to finish his tests. He refuse to check it over when the teacher asks him to do so. And I donot even remember how many times I asked him to do the same. But he said he didnot want to.