[coldtea]

>I'm stating a fact that we were talking about what makes a genius and you decided to make it about rape

Conversations move and branch out from their starting subject. That's in the nature of conversation.

But even keeping it on the same subject, sometimes people bring an example or a metaphor from a different area to clarify something about the subject. And sometimes they try to use something obvious or universally agreed as a good or bad counterexample to drive a point home. Which is exactly what happened here.

If we talk about computing and I bring an example from baking, I don't "make it about baking" anymore than the parent "made it about rape". If anything, the parent just made a single comment that just happened to use rape, he could have used any number of similar examples, e.g. arsonists or flat earth believers or Drake fans -- you fixated on his use of the word rape.

>there was an implicit derision aimed at the person you replied to in addition.

Only an imagined one. The only thing the parent did was to aim at a gaping hole in grandparents definition. No derision towards the person itself.