The devaluation is acceptable and normal. People who are of non-normative intelligence or ability (narrowly defined) are simply considered less-than, so it’s the height of insult to call someone “stupid” or “a moron” or “a person with a low IQ.” Likewise, people with severe disability are considered less-than, so it’s perfectly acceptable to respond to an argument you don’t agree with by saying “If you believe that, you shouldn’t go out without a carer.” (Yes, I have heard someone say that in a social justice space. I could almost see the sneer.) When I hear these kinds of words, it’s the hatred and devaluation I’m responding to, because it’s everywhere, and it has a concrete impact on people’s lives, including my life, the lives of people I love, and the lives of people I serve.