I taught in school for a short time. It IS the parents.
It is a complex problem and solution. Don’t narrow it down to one.
I did as I pleased and my administrative advisor and the principle ran interference for me. My school was all-in for the students and the teachers. I was 70 when I started teaching; and, was stunned at how difficult the government has made teaching. Few parents can be pleased. Few will work with the teacher in order get students functioning. Most don't even look at progress reports. Some beat their children raw. Our society is very sick.