I think Portia hit the nail on the head regarding the "wasting time".

I, too, have a 1st grader and a 3 year old and I hear the same type of complaints! I think it's because DD6 would rather be playing with DD3 than doing "busy work" because unfortunately most of her homework is too easy and not stimulating enough. And after a full day of school, I can understand that she's bored out of her mind and wanting to move on to something else. Now, if I go online and print out worksheets geared towards 2-4 grade levels up, she will do them all afternoon. She loves them. So I think the difficulty (or rather lack thereof) of the work is the issue, not that she has to do it. I've explained to DD6 that sometimes homework will be easy but she still needs to do it, just as she would need to do more challenging work as well, and that's just part of life. I've also told her that we need to do our work first before we play. At this point in the school year, it's finally beginning to soak in so I'm hearing less complaining than I did at the start of the year.