This resource is dropping woke bombs left and right (I’m into it). Extremely rich text.
… societal interpretations of and responses to specific differences from the normed body are what signify a dis/ability.
Not to glom onto this one pat definition, but it’s one of the many paragraphs that jumped out at me.
I still haven’t got to any part that is specifically challenging using “polite” language when speaking to disabled people about their disabilities. But with your question about why I might consider the term disabled a slur, and these links, I think I’m getting there…
EDIT: uhhhh nvm, the paragraph literally after the one I quoted goes into it, very specifically.
Some advocate for People-first language (a person living with disability), while many disability activists advocate for identity-first language (a disabled person).