This is a great post, thank you. I'm one of those engaged parents, and I hear this from teachers all the time (public school). Most parents simply don't give a crap about their child's education anymore. However, as a parent, I have seen a drastic change occur while my kids have been in school (currently 2 HS Freshmen, and 1 HS Junior).
I'm fortunate enough to live in a rural area where the public education system hasn't taken as big a nosedive as it has in other areas of the country. Still, I often hear stories of what goes on in class and what's being taught, and none of it would've flown when I was in school...and I'm not that old. Some teachers are bad, no doubt. But I've only ever met one teacher who was absolutely worthless, so I don't blame them. The system is broken, or at best, flawed and needs improvement. Judging by all the hand-holding politically correct bullshit that I read in the "real world" on a daily basis, I can only imagine what it's like in school. Personally, the voucher program is the best solution I've heard.