I don't use such colloquial expressions that tend to vituperate a large group of personages and cast them as a party to be stereotyped and ridiculed thereof because of it. It even gets offensive when some try and fail to acknowledge another's intelligence by uttering such pejoratives as "Wow, you are so smart, you must be Asian." or "You cook... you're so feminine."
I can hardly stomach hearing the words 'retarded' or 'insane' because of the way they are now inaccurately applied most everywhere.
I doubt anyone would care to use it, but I have fondness in calling such mistakes "a lack in cognitive reasoning".