I agree with the bolded, too, especially the part about parents knowing their kids the best. My dd1 struggles in math, but has all A's in her other subjects. Her math teacher does not especially "get" her and thinks she's slacking off when she's working really hard — she just does not have a mathy brain. We really work with her a LOT over math homework, especially DH, to keep her up to speed. If she didn't have math homework and our help with it she'd struggle much more in that class.
I think what I'd like to see is maybe one homework assignment in each class each week. So maybe Monday is math homework, Tuesday is English, Wed is Science, Thurs is History, Fri is foreign language/elective.