It's not frowned upon or bad to communicate however you want to. I suspect these acronyms are in part a hangover from the origins of Sasu where they would use other acronyms like CTB rather than the actual word so that the forum wouldn't get as much attention from people who are anti choice and probably actively searching those words.
I suppose it's a more gentle way of saying it too. Plus, there's probably a degree of lazyness and maybe just trying to fit in with the vernacular. But, I don't think most people mind that much. I don't think it's something you would be banned for- certainly. Except- like Deathsleep just mentioned, people tend to be careful not to openly disclose sources.