Sorry mate, no, you don't get to be clever by pointing this out. Nobody forgot. The point is that someone calling Nintendo's button layout 'the wrong way around' is referring to a 'correct' layout that is not as old, not as popular and not as ubiquitous. XY/BA is 27 years old and an evolution of the BA set-up which is 34 years old.
Nintendo's BA button naming legacy goes back to 1983
Every single Nintendo console or handheld has BA in that format (including the classic controller for the Wii, and even the Wii Remote in a sense since A is the main and B the secondary). BA in that order is by far the most common layout in gaming history, it's on the controllers of 700 million consoles. Second is Sony's shape motif.
Sega's buttons from 1983 to 1988 were named 1 and 2, they went with ABC in 1988 for the Mega Drive after the Famicom's, and when adding the six button controller much later (1993) they even shamelessly stole the 'separate set' XY motif from Nintendo's 1990 Super Famicom with XYZ.