I do get what you mean. I think generally parenting seems to be becoming quite lax in quite a few groups. Sometimes I feel I’m the only one with high expectations of children’s behaviour (which I know is not the case).
My child is autistic, he’s very bright but struggles a lot in certain situations so I fully understand meltdowns and have every sympathy with parents having a tough time. It’s difficult for us to go out without incident but what we are not is passive in our parenting. We work very hard to avoid / help in a meltdown.
Examples I’m talking about are going to the theatre, we fully prepare eg. Ear defenders and will take son out so as not to disturb the experience for others if he needs a break. But it seems I’m often alone in being interested in others experience, others’ kids are loud, jumping on seats, leaving rubbish behind. These are all things I find unacceptable when others have paid for an experience.
We’ve had play dates where other children run riot around my house where the parents don’t even seem to notice what I deem to be unacceptable behaviour. Things like chasing my animals, smashing the window in our playhouse, throwing food in the house. No SEN that I’m aware of.
I’ve been called fat at school drop off whilst the parent watches with an ineffective ‘that’s not kind’.
Being a parent of a child with additional needs I’m aware these needs might not be obvious and try to be compassionate but I’m actively trying to teach my child what is and what is not acceptable but increasingly feel alone in this!
I’m now ready to be ripped apart like the OP.