@Rengar It's mostly people jerking off about how much incest gets them off, or complaining about how bad it is.
@Flyingpantsu "The world didn't end" because openly incestous families were slaughtered on a regular basis, or merely had the shit kicked out of them until they fucked off. Most of the time, it was because they embraced "wincest" nonsense as correct and used it as justification to do stupid / malicious shit until people got angry enough that the knives came out.
Political history is full of this particular cycle. See: some of the Egyptian dynasties, pretty much all the Greek city-states that promoted it, several of the Roman families, quite a few Medieval and Rennaisance royal / noble groups, etc.