The euphemism treadmill.

(I think the conversation here is more about etymology than entomology)

“Sped” is often how teachers refer to special education now too. I was a “sped teacher” for a bit. Referring to a child as “sped” would be gross and dehumanizing, but I think referring to a “sped class” isn’t considered pejorative.

It’s weird how worked up people get about “political correctness.” If you call someone ‘r-tarded’ you’re doing it to upset them, and you are also communicating that the status of having an intellectual disability is so degrading to be considered an insult. I’ve worked with lots of intellectually disabled adults and children - I don’t know that I would want to compare those people I loved and cared for to someone that I would want to insult.