I'm not denying that severely disabled people can have meaningful lives, I'm saying that the crowd who say "autism is not a disability it is a completely neutral difference and all negatives associated with it is the fault of neurotypical society" are the people who can express themselves fluently with language, and also the people for whom autism is not a disability. But that there is a large proportion of people with autism for whom it is a disability, as you seem to agree.
Just because there are ways to make life easier or harder for disabled people doesn't take away the fact that they are disabled...