Ditto for a lot of the words we use as synonyms for "stupid".
There's actually an entire ranking for those with disabilities - just below a "normal" person was the "feeble-minded", which ranked ahead of a "moron", which was more functional than an "imbecile" which was the last step before an "idiot".
This was all common parlance in the 19th and 20th century.
So explain to me again why retard is specifically offensive.
The reason "retard" is more offensive to people with mental disabilities (even when not used directly as a slur) is that its use in that context is more recent than the use of "idiot" or "imbecile".
That is all. Really. Give it a few decades and we wouldn't be having this discussion because no person with mental disabilities would feel offended by anyone using it as a mere synonym for "dunce".
Of course so-called Internet feminists might still demand your head on a silver platter even then, but (in stark contrast with actual feminists) nobody should be paying attention to them to begin with, even if they make it hard not to.
There's actually an entire ranking for those with disabilities - just below a "normal" person was the "feeble-minded", which ranked ahead of a "moron", which was more functional than an "imbecile" which was the last step before an "idiot".
This was all common parlance in the 19th and 20th century.
So explain to me again why retard is specifically offensive.