For me, it is grossly insulting to people profoundly affected by autism (and their families/carers) to pretend they have anything in common with those who self-identify as ND.
@SlipperyLizard
If your in-laws have not been diagnosed but use it as an excuse to not get on with things, that is wrong. I can't abide it when people have problems but don't seek help.
But, I don't agree with your comment highlighted above as I don't think anyone with a mild ND would consider themselves to have much in common with someone profoundly affected by autism, beyond perhaps being able to better empathise.
It does, however, highlight the issue with using ND as an umbrella term.
People with mild ND are treated as if they are making it up, or just not able to cope - it's the latest version of "There's no such thing as depression, people just need to cheer up".
But ND, whether mild or severe is no different to any other umbrella terms for other types of conditions / illness / disabilities.
You wouldn't say it is grossly insulting to people with schizophrenia or bi-polar to pretend they have anything in common with someone who suffers from mild GAD, but they are all classified as mental health conditions.
The same could be said for people who are quadraplegic or have ALS to be classed as physically disabled and pretend that they have something in common with someone who has mild spina bifida or who has had an amputation but can live their lives quite fully.
Cancer survivors can range from those who've had a stage 1 melanoma, fully removed in a biopsy to those who've gone through years of chemo and radiotherapy to survive stage four breast cancer - but they are all cancer survivors.
ND is no different - some of us have what would be seen as relatively 'mild' forms and we just need a little bit of medication or coaching support, or to understand our condition so that we can manage it in today's fast paced life. Others are more profoundly affected, and need a lot more support, but it is not insulting to recognise both as ND conditions.