This is so interesting.
Practice, assessment or extension of a lesson - these are all very worthwhile goals. And I am not in the least anti-formal learning, having been a complete swot as a child and having carried this into adulthood. But what is the reason why these goals cannot be achieved in school hours instead of in the evenings? (And holidays - we have holiday tasks.) I don't myself think that standardised testing or a full curriculum are adequate answers to this question.
I also wonder if part of the disconnect between the teachers who are saying, schools don't assign hours of work for 6 year olds, and the parents who are saying, my 6 year old has hours of work, is not laziness on the part of the parents - but rather that the parents are putting so much time into the homework to assist their children, and never complaining about the burden, that the teachers don't know how long it takes or what the ability level of the child is - so actually undermining the goals.
I know that teachers also want to see parents engaged in their child's learning. On the other hand, I always assumed that I would provide a lot of education and extension after school for my children, just as my parents did for me. But I didn't realise that homework from a kindergarten level would actually interfere with this goal.