to anyone who wants to argue about how language changes and how words get retired and if we retire this word another will come along: First of all, I don’t believe you in this case. In the past 10-15 years, the word has fallen off in use, and the words that replaced it weren’t offensive in the same way.

I don’t understand why you think this argument, which I’ve heard described as the Euphemism Treadmill, doesn’t apply to this word. Retard is used to describe the slowing of something, like fire, without any insult to people. It’s just a word. As you point out, that word can be, and is, used as an insult which causes harm. However, any word can do that. Take “slow”, which I used above as an example. If it became the new slang insult for people of below average intelligence would you ask that people stop using it? It sounds silly to think of today, but that’s just because we aren’t used to hearing it that way. There’s nothing stopping a new word from taking the place of an old one, and retarded is not special. I guarantee you if people used it to laugh at others or said it sharply it would become just as hurtful.

We used to call people without jobs or shelter bums, then homeless, then housless, now temporarily unhoused. Once everyone is saying temporarily unhoused what will the next word be?

We’re absolutely in agreement that slower people are people too and deserve to be treated with respect. However, the fact that intelligence is a sought after trait that you are ridiculed for not having is the root of the problem, not the word used, and I don’t think this word has some special ability to get around the euphemism treadmill.