So what you're saying is don't bother doing the easy work in school? My DC are required to do whatever homework they bring home, regardless of how easy or difficult it is. Just because they may be above grade level doesn't mean they are above doing what is expected of them in their class.
Actually, I didn't say anything about what they should do in school. There, the considerations are a bit different: for a child not to do their assigned work might be disruptive, and the teacher is right there and better able to determine whether the work is appropriate. At home, neither of those is true. I accept a responsibility to make sure my child does tasks assigned by school if they are educationally valuable, but not just because the child has been told to do them. Absolutely, I'll tell my child not to do something, if I consider it inappropriate, and I'll explain to the teacher why I've done so. If it's something that would only take a few minutes, leaving plenty of time for appropriate activities, I might just let it go; but the OP was saying that the inappropriate work was making it impossible to fit in appropriate work. In that case, I think the responsible thing to do is to substitute.
I think the aim of school is to get children to the point of being able to take responsibility for their own learning - not to teach them to be obedient.
I'm sorry, I didn't mean at school. I meant for school, meaning home work as well. I don't enjoy when my children get busy work, but in every day life, they will both be faced with work that isn't stimulating or worth their time. They may be in a job that it is required to do such. I don't believe in teaching them that they only have to do that which I, as their parent, see as beneficial.
The OP was stating that the homework given by the school was not at the child's level, and the extra work given at home was more challenging. If I was going to tell my DS's teacher that he was not going to do the easy homework because I am giving him more challenging work, then I might as well homeschool. I don't see how telling a child not to do the "easy" homework is teaching them responsibility. If the child needs harder work, then it's up to the parent to go to the teacher and/or the school to work out a better situation. While I agree that parents are responsible for their children's learning outside of school, I don't agree with my child not doing school assignments because of the level of difficulty.
I'm not trying to start an argument, but as a former teacher, it's frustrating when a parent dictates what a child should or shouldn't do without coming to the teacher and/or school first, whether it's during school or after school assignments.