The only thing I was "disparaging" was your grasp of the standard meaning of phrases such as "very recently, culturally".
You could have avoided the issue entirely by using clearer language like "in the last 40 years."
The idea that I was claiming things older than me are "irrelevant" is nowhere near orbit of anything I wrote.
(Also I don't know if you are American but I am and the median American is around 39.4).
I didn't use the phrase "very recently". You did.
I said the word is recent, linguistically and culturally. I said it was "fairly new". I also said when it was popularized, in terms of actual decades (70s-80s).
You've chosen to die on this particular hill of whether or not something is "recent". I don't know why.