It's the de facto shorthand for Raspberry Pi. Language evolves; it's a beautiful thing to behold evolution in ones own lifespan! I have found something my mother used to say to be very helpful here, if you're feeling particularly curmudgeonly about such things: "you can be right, or you can be happy."
She went on to say that being "right" isn't true as often as one thinks, and in any case, forcing your "rightness" on others can sometimes exclude you from groups, opportunities, and experiences, which takes away happiness. Being happy doesn't mean abandoning your principals, either. It means knowing when it's worth picking a battle versus letting something go because you may, in fact, be wrong according to those in the know, and in any case, when principals aren't involved, it's often easier to simply let it go.
This is all a polite way of suggesting what another might say in three semi-rude words, and that I'll only repeat here to potentially prevent someone else from being abrasive, not because I mean too say them directly myself: "get over it."