What you wrote with:

"almost all of their time trying prevent a riot from breaking out"

is quite similar to what I wrote with:

"The best can hope for from a K-12 school is that it will do no harm.

"Find a school that has a nice 'social atmosphere' and otherwise is RELAXED, e.g., with as little homework as possible."

So we are at least partly agreeing.

What to do about a school with knife fights in the classrooms, drug deals in the halls, and pimping at lunch time is to get the hell out: Such a school fails on "do no harm" and "a nice 'social atmosphere'".

If just have to leave and can't afford a wealthy neighborhood, then pick a small town in a rural, farming area in one of the more northern states; there essentially any school will do no harm.

Also good, pick a college town. Even if sweep floors, flip burgers, wash pots, and act as a security guard, will be able to do a terrific job getting children ready for college and life.

My good news is that don't have to move to some neighborhood with all millionaires. Instead, quite sufficient is JUST "do no harm" and a 'social atmosphere'. Academically relaxed is also good.

This is a radical recommendation: For good work in actually learning for college and life, mostly don't depend on the school. Don't mostly depend on the school even if in one of the best school districts in the country or even are sending children to one of the best private schools.

Why? Again, yet again, to repeat, bluntly the K-12 teachers don't know enough to teach much of anything to be taken very seriously. The K-12 years are some of the very best years for learning, and it is a grand disaster that those years are turned over to the K-12 system and, thus, largely wasted.

Also implied but not stated was, get the heck into college level material ASAP. In the US, the good academic material starts in college and continues into graduate and professional school. K-12 is wildly different and, academically, is a really bad joke -- mostly can just skip it. For most parents who want good education for their children, this is radical but good advice.

With my advice, careful parents, and a one-room school house in a serious, rural farming community will totally knock the socks off ANYTHING in formal K-12 education.

For your:

"Also, it can be very hard to support real learning at home if you are a single parent working two or three jobs to make ends meet."

True.

So: (1) Young people, listen up: Work however hard is necessary to form stable marriages and, really, stable, larger families. Marriages and families are IMPORTANT. Again, listen up.

(2) Unless you want a series of disasters for the rest of your life, delay having children until you can form a stable marriage.

(3) In the home, set up a 'culture' of learning instead of TV, cars, fashion frocks, popularity competitions, cell phone gossip, pop culture, fast food, sports, wild parties, etc.

Then, get the children started and going on learning, largely independently, ASAP. Then the children can learn on their own time with minimal time from parents, so little that there still is a chance for a single parent.

But this matter of a 'culture' of learning is just CRUCIAL. If there is any doubt about the culture in your home, then disconnect the TV. Keep children away from 'pop culture'. Emphasize LEARNING and, then, curiosity.