Ma'am, we have to understand that teachers are humans like us. They have personal lives, they have priorities, they have to earn a living for themselves and their families.
Even at their most "regular" level, teachers are already doing superhuman stuff. And there are those who really rise above the ordinary who deserve our utmost respects.
But the thing is, kids are the parents' responsibility (I'm a parent myself and I'm doing my damdest for my kids). We can demand that teachers teach our kids the basics of language, science, and arithmetic but discovering what our kids are capable of and supporting them all the way to attain and exploit their potentials, well, only us parents are capable of it.
I have 2 kids at home, my elder daughter's teacher has 40 kids in the classroom. Who is more capable of looking out for my daughter? I am.
I take responsibility for my kids and how they will turn out as adults.
Teachers nowadays can't actually hope to teach children of diverse abilities to achieve their potential, unless it's a one-on-one session for a particular talent, like that piano teacher teaching piano lessons to my daughter.
Peace to all! :)