[lolinder]

The article you link to discusses "lunatic" being offensive when used in law in its original sense to refer to real people with real mental health problems. Whether that is offensive (and I think it probably is) is a completely different question from whether its modern, colloquial use is offensive.

The word dramatically declined in popularity through the 19th century but started climbing again after ~1995[0]. The recent increase in usage is driven entirely by a much milder, colloquial meaning of "wildly foolish"[1].

I think being offended because our great-grandparents used the word literally is a bit silly.

[0] https://books.google.com/ngrams/graph?content=lunatic&year_s...

[1] Meriam Webster identifies the older meaning as "dated": https://www.merriam-webster.com/dictionary/lunatic