I think the message title is rather exaggerated.
I agree the post is very judgmental , understandable, but who makes the rules about whether you have to get out of your car to socialise when you drop a child at school.
If OP 'hates' the parents, steer clear surely.
I wouldn't overtly project my judgments onto my child, especially with such a strong word as 'hate'. I think there must be some more elements to the story, lost friendship between women, anger and bitterness which has nothing to do with a child and their school mates - these usually change in secondary anyway.