I think what is missing in this discussion is pushing information in when children are ready and sitting back and letting them get there in their own time when they are not. I.e. Using a golden window of opportunity.
My dd at 8 and in yr4 is suddenly interested in maths and blasting through her timestables in a way she wasn't able 6 months ago. Maths is suddenly clicking. She's willing and able to learn and this is the time to have fun at home with extra maths.
Primary school teachers are aware children need to hit a series of developmental stages before it is even possible for the child to grasp certain concepts taught in the primary years. These stages vary wildly in some children by perhaps two years and is entirely separate from IQ or learning potential in secondary. By all accounts and judging by Trifles posts, she as a secondary school teacher is not aware of this. For you can try to teach a child something until they're blue in the face and yet still they are not able get it. Then 6 months later, teach them the concept once and they grasp perfectly the first time around.
By the time children reach secondary school, their ability to learn, analyse and perceive is already well honed. It is important not to put them off reaching this learning potential before they even get to secondary by making school work a chore and a battle at 4/5/6/7. Giving children a well rounded education outside the classroom is of equal importance at this age. And far more beneficial than a constant battle about a piece of homework, which at this age has far more to do with training the parents to become accustomed to helping with learning than consolidation for the child.
Now that dd is in yr4, she is noticing the odd child, who is not doing their homework. This is because the children lay their work out on their desks for the other children to view and leave positive comments on a slip of paper. This is a clever way to peer pressure children into doing their homework and give them the opportunity to learn to peer critique others work in a controlled and positive way. I do believe that by 8 and 9, it is useful for children to be doing their homework and for parents to be helping them. For getting used to setting time aside and doing regular homework will stand them in good stead and assist with the transition to the more formal structure of secondary school.
Unless extremely fast at learning, a child, who never does their homework, never practices their times tables or spellings outside the classroom is a child, who will likely struggle in secondary. This is very different from missing the odd bit of homework at 4/5/6 or putting the books down for a couple of months because the child has reached a plateau or is finding school exhausting. Once the child has been allowed to rest or get to the next development milestone, it is then more likely to be possible to pick the books up two months later and whizz on to the next stage. Pacing a child's learning in this way is giving the child a wonderful sense of achievement rather than a very long trip to the dentist. And as a parent, we need to be sensitive to this as the teacher cannot be expected to be entirely responsible for the education of 30 plus children.
To say otherwise is frightening to already stressed and worried parents and absolute piffle. Homeschoolers feed the information when their children are ready to great success, which is why so much of the homeschooled children's time is spent outside of any formal classroom style activities.