Really, why is this acronym so fucking popular? It can't be only because of Reddit, right?
Nobody had problems with DP and started calling it DiPe, so what's so bad about just fucking writing SM?
And no, there's no "it rolls off the tongue better!". You're not even supposed to say this shit out loud in the first place. People don't say "eff-err-el-gee are my favorite games" or "dee-pee-peetee were shit", so you shouldn't have any reason to say "soo-moh" in real life when you could just say "Sun and Moon", unless you're a turbo autist.