Because using three letters is faster than using eight, and that’s how internet communication works - the shorter, the better.
And because while this indeed is an English speaking section, it’s the internet. And in the internet English isn’t just for anglophones, but it’s an international language used by (almost) everyone.
LOL. We use that, but not as a slur, just as a abreviation like “pole”. But we can’t use “pole” because we can’t genderise it in speaking. And so we have “polac” as in polish man instead of “polonez”, “polaca” as in polish woman instead of “poloneza”, “polaci” as in male or mixed group and “polace” as in female group
in US everything is racial slur… somehow even he or she has become slur and violence if you “misgender” someone. or if you are not using they/them for non binary…
Tbf, no one really uses it as a racial slur anymore in the US anyways. That died out a long time ago. We use “japs” in the kitchen where I work, though it’s for when jalapenos get added to something. People aren’t really knowledgeable of it being an antiquated slur, and have removed that meaning from it.