Because it creates a binary when a) it's a spectrum and b) high/low functioning dichotomy is not a constant. Every day needs can be different. Sometimes people are low functioning during child hood and become more functioning into adulthood. Sometimes high functioning autistic people become low functioning later in life. Some people can function very well when they had adequate support but the can't function at all when support levels fall below a threshold.
Reducing the conversation to high/low functioning also limits people's understanding and compassion of autistic people. The sibling commenter to you said they believe high functioning autistic people don't deserve to have a say over matters concerning autistic people, which is incredibly troubling because that just becomes and avenue for silencing autistic people; if having the ability to speak up for yourself means your opinion isn't valid, then that gives license to use and abuse a population, as autistic people often are.
Because it creates a binary when a) it's a spectrum and b) high/low functioning dichotomy is not a constant. Every day needs can be different. Sometimes people are low functioning during child hood and become more functioning into adulthood. Sometimes high functioning autistic people become low functioning later in life. Some people can function very well when they had adequate support but the can't function at all when support levels fall below a threshold.
Reducing the conversation to high/low functioning also limits people's understanding and compassion of autistic people. The sibling commenter to you said they believe high functioning autistic people don't deserve to have a say over matters concerning autistic people, which is incredibly troubling because that just becomes and avenue for silencing autistic people; if having the ability to speak up for yourself means your opinion isn't valid, then that gives license to use and abuse a population, as autistic people often are.