Edit: A few people have interpreted the title as serious, so I wanna clarify that it was meant as a sarcastic joke about how little sense the neurotypical world makes to me, but it is still legitimately me asking for help understanding said neurotypical world.
Was having a conversation with a friend today about why I seem unapproachable to people online. Apparently it's for 2 reasons.
One is that I say "K." all the time, as a short way of saying okay. She pointed out that most people find this rude and offensive. This kinda baffled me, because like why? She explained that like, if somebody were to give a long emotional speech and I just responded "K." that would be offensive. That confounds me. So it's rude in one context, and neurotypicals have decided to be offended by it in all contexts? But the reason it's rude is what confuses me more. Apparently it's considered lazy because you could have just typed out the word, but like, that applies to all text speech and nobody's mad about people shortening those words.
But it got more confusing when she explained the second reason, which is that I end all of my sentences with proper punctuation, which she said "makes people feel like I'm done with the conversation and not interested." But just a second ago improper grammar was rude, and now proper grammar is rude instead.
It baffles me. You can't just use proper or improper grammar. Use too much improper grammar and you're lazy and rude. Use too little and you're also rude. But you can't just use any improper grammar, you have to use the very specific subset of improper grammar that's been deemed acceptable and not lazy (even though it's exactly as lazy as what they do consider lazy.)
To be clear, I'm not bitter, and I'm definitely gonna adjust my behavior to hopefully seem a little less rude to people. I think that's just a nice thing to do. I just find the neurotypical mind utterly fascinating. I don't think they even realize how many contradictions exist in the social rules they all so easily accept.
I'm not sure how helpful this will be, but I think it is misleading for you to think of these things as "rules". Calling them rules implies that people know what they are, and try to abide by them. But I don't think thats whats happening.
Since written communication conveys so much less emotion than verbal communication, people tend to read more into the textual form to infer things like emotion or intent. There aren't specific rules for this, people just pick up on patterns. For example angry or excited people tend to use capitals to "sound louder". People talking casually tend to leave out some grammar. Friendly conversations tend to have more long rambling sentences, as opposed to someone trying to prove a point with concise, well punctuated sentences.
So I think what NTs are doing is just subconsciously figuring out these patterns to determine a likely emotion/intent behind messages.
To me, "K" isn't rude for the reasons your friend tried to list, but it does sound "colder" to me, probably because my brain sees a pattern where the people who are not interested in talking to me will tend to use short succinct responses, while people happy to talk will use longer form.
But a huge part of communication, especially online, is just getting used to the people you talk to. It's happened many times that someone who seemed grumpy to me at first turned out to be very friendly, etc.