I think the major issue for me is with very young kids--but maybe that's just because my daughter is only 3. It's the flashcards my mother-in-law bought (which DD uses to throw all over the floor and "skate" on) and the your-baby-can-read systems that my aunt recommended (because I haven't told her that DD has already taught herself). And, to a lesser extent, the electronic games (yes, including starfall, which DD uses) that are meant to teach but are disguised as toys. I don't think a limited amount of any of these things is awful...but I can definitely see them being misused.
For older kids, I think the issue is just whether they have enough free time to play. Free play is absolutely essential to a child's (adult's?) mental and emotional health, creativity, empathy, etc. Sometimes (typically?) free play is educational. I know I loved logic puzzles and other "smart" toys as a kid. There's nothing wrong with that.
I guess the other issue for me--and I guess it shows my unschooling sympathies--is that I don't think it is helpful to force children to learn things they don't want to learn. More or less ever. I think kids learn so much better when they are into learning.
I don't think there's anything wrong with a longer school day, depending on what the school day looks like and whether the kids enjoy it. I do think there is plenty of evidence that long school days full of discipline and drilling produce children who do great on tests but have mental health problems.
