I’m quite sure there is nothing I could say to convince you, so I’ll not try.
But, just to make fun of you, I’ll note that your second bullet point is about bad parenting…
Also, your third bullet point is precisely the point (with a bit more explanation). But, the real problem is when the parents have that attitude. When the parents are good, then it is almost impossible for anything else to matter. But, when the parents are bad, then everything the school does just reinforces it.