Chiming in as another former teacher.
I agree with one poster, weak teachers will always have bad classrooms.

Young teachers will usually be a little hot-headed, as they work to get their sea legs.

But some of my kids openly admitted that there were one or two choice students who would intentionally bait the teacher to get the lesson plan off track. (delay a test or give the class time to prep for a test in another class, for example.)

And some students were just wormy pricks.

I taught for two years at the same all-boys high school that I graduated from.
I agree with the commenter who says the single-sex educated tend to be more socially awkward. I and many of my classmates were.

In addition, while I was teaching there, the school principal wanted to open the school up to girls (but was prevented by the trust that helped fund it) based on the belief that it would have a calming affect on the boys.

I grew up in Los Angeles, and this specific scenario happened a few times.
Conserve, Conserve, Conserve.
OOOPS
We're losing too much money!!
Charge More for Less! Charge More for Less!!