@Junpaku The origin is still a technical term from an old timey medical standpoint that was twisted into an insult colloquially and then it fell out of standard use for its original context because of that. If the timing of the official use ending is the only difference, the outrage is probably a bit excessive from being too fresh in the mind as the only one like that. I think the real problem is probably that, it got left in a state of being both official and insulting slang for too long before the newer official alternatives were taking root everywhere they were supposed to.
Now, people who were invested in changing that ambiguous state are still battling its colloquial use, but in that state it's pretty much already in the same boat as dumb, moron, idiot, etc. At the other end of all that, the acceptable term just keeps swapping out because this is, and probably will always be, a repeating cycle. Things just aren't going to slide into that same "softened" state you mentioned, I guess. I think handicapped has come and gone, people are at least getting twitchy about disabled if it isn't already completely unacceptable? That's all that bothers me about this, if it has to be a problem for even one of them, then it should be for the others that share this origin story.