In the words of Popeye* ... "I am what i am!"
*(in case you are not sure who Popeye is, he is the cartoon sailor from the early 1930's.
Famed for his use of spinach to aid him in his fistty cuff battles with villains and especially Bluto, his arch enemy.
He also had a sweet strange looking girl friend olive, a baby called sweeps, an obese hamburger eating friend called Wimpy and last but not least an invisible cat friend called Cheeba).
...meaning, what makes me is me, categorisation sometimes can lead to assumptions
that lead to mistreatment.
I feel that categorisation is there so that those who need support get support,
however the categorisation is not all encompassing nor a competition.
I would say that in some areas, people who need no support can still be more disabled than
even those who require high level of support (for example. someone with Asperger Syndrome can have sensory impairment but not need any support, where as some who are low functioning may need supported living but may not suffer from sensory impairment).
It is what it is.
There is also the debate that discusses IQ and incapacity as it relates to employment.
Some low functioning people with autism spectrum disorder may find good employment where they are treated well, and they are intellectually stimulated fairly easily - so employed to the level of their capabilities.
However, some people with Asperger syndrome may have high IQs but not be able to find employment in any area that requires their level of intellect, due to the amount of pressure due to work load and psychological stress.
So inevitably end up unemployed or underemployed.
So the disability causes much higher level of disability in them, even though it is not perceived.
So yep, ascertaining how severe a persons disability is, is a much more complex matter than simply slapping a label on someone according to how able a person is at doing normal every day tasks.