When my moniker was used s a synonym for “retarded” as in any body who disagrees with that poster is “retarded (=) developmentally delayed, … (=) idiotic, (=) dolty, (=) ubiquitin-ey, (=) asinine, (=) insane,(=) bi-polar, (=)depressed, …” I was hurt .
That I understand.
It is not hard to understand why those with a condition are offended when their (or their family member’s) condition is used to insult others as a synonym for “idiotic.”
Maybe not, but it it is hard to understand how the term “retarded”, which been obsolete in that context for decades, would be offensive.