I think it is a matter of habit. It is the responsibility of the parents to build up this habit for the kids, not the schools.
My daughter is now in K3, p.m. class. Every day after school she will have some snack, then take a bath, watch TV for a while and then I will say "do your homework la". Then she will take her homework out and do it on her own. I will only check it after she finishes, and sometimes if she doesn't know something, she can ask me. She has around 1 - 3 homework every day. And it takes her around 10 - 30 minutes to finish all. I think if this habit can keep on when she studies in primary school, then homework should not be a headache for us.