A guy I went to high school with used to claim that calling someone “cute” was an insult, because “cute” originally meant “bowlegged.” According to the OED, that’s wrong. “Cute” is an aphetic (initial vowel dropped) version of “acute,” and originally referred to someone sharp, clever, or quick-witted. A secondary meaning lists “cute” as a synonym of cur, a worthless dog.
Of course, that’s not the sense in which we most commonly use the word today. If I refer to someone as “cute,” I don’t mean bowlegged, clever, or dog-like — I’m usually referring to someone’s physical appearance. (There’s a sarcastic version — “Are you being cute?” — that refers back to the original meaning, but tone of voice usually makes it clear which meaning we intend.)
The genetic fallacy is the argument that because a word or phrase once meant something different, it continues to mean the same thing, regardless of how usage has evolved. The legend that a “rule of thumb” describes the maximum thickness of a stick with which it was permissible for a man to beat his wife has been debunked repeatedly, but even if it were true, it’s not how we use the term today.
Genetic fallacies aren’t always about language. Australia may have been settled in part by British criminals (as was Georgia), but any conclusion about today’s Australians can’t rest on the legal status of its founders.