@Gerrataere My husband was diagnosed with ASD at 11 years old. In the days of proper CAMHS funding. He was seen by 7 'specialists', half of whom agreed he had it. half of whom did not. He is a champion masker and even now appears 'normal' to the general public but when he is with me obviously stims etc. His report as a child details obvious behaviours (inability to read social cues, sensory issues) etc but still some professionals claimed he didn't 'meet the threshold'.
I got diagnosed via insurance at work but the signs were always there, like many ADHD women everything was 'fine' until I finished uni and the demands of life and work caught up. Because I used to be great at exam (last minute hyperfocus FTW) nobody thought anything of it and let me get away with constantly not finishing my homework. forgetting stuff etc. Now I have to be 'on' 5 days a week at work and it's very draining.
Personally I think 'overdiagnosis' isn't really relevant, but the consequences, 'excuses' is a different matter. I had quite a few 'friends' who for example are always late 'teehee sorry ADHD thing' which I find offensive as I'd feel bad about keeping people waiting!
Even DH and his ND band of merry men don't want to play video games with a particular person who always insists on getting his own way, gets very angry when he doesn't, stubborn etc etc. Maybe his autism is a reason for his behaviour, but that doesn't excuses it. They are all ND and they don't want to put up with it, let alone other NT people.
As much as MN blathers on about ableism the biggest issue isn't 'NT' vs 'ND'. It's among ND people themselves, there are so many of us, we tend to make friends with similar people.
There is always going to be argument about what people deem as a reasonable adjustment, what is acceptable behaviour, because each ND person is so different you are basically having to understand all of them on their own merits. So on MN, 'people should be accommodating and understanding' I don't know IRL what that would be like depending on the behaviour shown.