I think this is one of those 'perfect storm' situations where there are a myriad of issues underlying one single result.
Looking at it from my (42 year old) perspective, and this might be a little oversimplified, but here goes:
1. Mainstreaming for kids with behavioral issues. Yep, big one here. When I was teaching preschool, part of my introduction to parents was explaining my philosophy: it was my job to 'ground' the children's experience of being in the preschool setting so that the kids could have room, emotionally, to learn. Many of us know that kids whose needs aren't met, *including a sense of security*, have a harder time learning. It used to be that children with a propensity to act out violently were in a separate group or even a separate school, with instructors who were trained to deal with aggression. Fast forward to the present: last year, one teacher friend of mine was happy because during the last rounds of teacher union bargaining, they "finally got a budget for defensive gear". This woman was a teacher of fifth grad students and told me she'd had kids completely trash out the classroom in rages, destroy computers and other valuable equipment. She was happy she could actually have some gear to protect her own body if need be while she was clearing the other kids out of the room.
Inclusion of kids with behavioral challenges should be a graduated affair, with kids meeting certain performance pars before being integrated into the mainstream classroom. Instead, the inclusion comes on the backs of the kids whose learning suffers. How easy is it to concentrate on your homework when the student next to you might just chuck a chair at your head because they act out and are still allowed in class. One thing to consider....
2. Screen time in general. Your husband had it right, A.. I'll argue that it's not just video games, but that it's 'screen time' in general. I'll be honest-- I know my butt got a bit bigger after we bought a laptop and made it so that I didn't have to sit down in the basement office to do what I'm doing now. Volunteering at the school library-- many kids take a class (English, media literacy, etc) in there, and I've seen them do a lot of 'frittering away' time on their own (this is often boys working alone-- the girls tend to work in groups and chat about what they do/find online). Video games do a great disservice in giving people a false sense of proficiency about something which is more or less a half-assed non-skill (Guitar Hero, for example--which teaches us that you can press a few buttons and make the appropriate noises-- what happened to getting some friends together and making horrible sounds in the garage, being *with* each other and actually having to work at mastering an instrument?).... So, yes, there's a lot of time when boys who are home alone-- who should be doing their homework-- are online with games and other pursuits...which leads me to~
3. How we set our children up to be passive receptors instead of thinkers. Think about it, even at age 0 we are training our kids to be entertained. Baby kicks high enough at a mobile and it lights up and plays a tune. Baby learns to press buttons to make things happen. Sorry, but this is NOT actual learning-- this is training kids to do what monkeys in labs do. Instead of letting our babies and toddlers explore their worlds on their own, in their own time, at their own stages of development, we jump in and try to make things just right. We can't even stand to watch them fuss and be frustrated because they can't sit up-- instead of letting them be, letting them develop the muscles in their body to do this, we squish them into a baby seat. We put on videos for them, in the hopes they will be smarter. I'm probably going to offend someone, but here goes: parents these days are so damn stubborn about picking up a book to *learn how babies and young children learn*. It's not with toys that are flashing and singing and entertaining, it's with simple, real objects which allow the baby to touch, taste, interact with and manipulate-- three dimensional objects. Not videos. Not noise toys. Not the screens I see parents handing to ever-younger children to 'keep them busy' while mom and dad do what needs to be done. We even entertain instead of providing guidance and discipline, and we are doing it younger and younger, with a lack of knowledge of our own on how children develop. (Grrrr.... this one frustrates me to NO end!)
If we don't allow our kids to be bored, to make their own entertainment--which, left to their own devices, they are incredibly good at---think about it-- these are the BABY STEPS of a child thinking and analyzing for themselves, for their own intrinsic interests. If we don't honor that, how do we expect them to start paying attention and learning and critically thinking about the stuff *we* think is important?
4. Learning style is left out. Honestly, I think some kids would learn the rote information we teach (multiplication tables, for example) running around the track like soldier, doing a cadence of call-and-response information led by a teacher and sung back by the students. Kinesthetic learners need a way to be accommodated. My dad's side of the family is rife with bright learners who NEED to move to learn. One sister did all of her college studying on an exercise bike so 'the information would actually get to my brain'. I have a homeschooled nephew who could not learn to read sitting still, but did well when he had something to rock back and forth on. This is a very real need which wise teachers do address, and will seek out therapeutic tools for these kids which work in the classroom (milking stools, rocking seat pads). But how many don't? I learned that with younger kids, some do better at group story times if they had a small something-to-do with their hands instead of being forced to sit and pay quiet attention. This is such a struggle for so many kids which is not being adequately addressed.
I have more ideas, but this will do for now... have to get Kiddo ready for school! (and it's important for me that he gets to school on time, so off I go).... really interesting question A.. I'll enjoy looking at the responses later.
Oh, one last thing; part of the job I do in the library is to put 'level' stickers on books, so that kids can find material at their reading level and be successful. The last librarian actually put the *wrong* color stickers on the books so kids wouldn't 'know' where they truly were, so they 'wouldnt' feel bad' about being an early reader. What a nightmare. I am correcting this with the correct labeling, but this is what I come away with-- what's so appalling about having an accurate assessment of one's abilities and addressing things honestly when a child needs improvement in an area? The 'feelgood' thing keeps our kids dumbed down, much like your friend's daughter's school; by not making things challenging, by just accepting that she can 'do enough' instead of working WITH her to help her master those harder concepts, she's going to feel better, not worse. Kids do feel bad when they aren't 'the best' at something-- I get it-- however, not addressing this will only make it harder when she gets older and more of those concepts appear in the presented material. By not addressing areas of need early on, they do tend to snowball.
As to parent culpability-- I think there are so many variables in that realm that it would be difficult to quantify or even begin analyses of that problem. But books like The Self-Esteem Trap and Nurtureshock are a start.