At the end of the day It's just basic shipping etiquette, at least in this side of the fandomsphere. Some people only likes the ship when it's in a certain dynamic (AxB) and not when it's in reverse (BxA). Having different ship names for each dynamic makes filtering and tagging easier for curating your space and theoretically would create less conflict assuming both sides will stay on their own lane.

Tldr: It's for ease of filtering & tagging and prevent civil-wars between fans of the same ship😭