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.
As far as I know, I am neurotypical, so mind that when reading my comment.
Regarding the title of your question:
Because neurotypicals are the majority of people. As usual, majorities set norms and actively or passively decide upon common concepts like ethical or societal rules.
Regarding the issue you described:
Even though it might seem exhausting, I think it's important to see people – regardless whether neurotypical or not – not as a homogeneous mass but as a highly variable mixture.
Sure, even then there are common rules like don't punch people. But those are the broad and general ground rules.
Then, there are the nuances, which can be highly individual.
In your example, regarding the punctuation, use of grammar as well as verbosity of replies, I would react completely different than your friend. I wouldn't mind any of those things, which seemed rude to her. Okay, maybe I would feel like I weren't given the attention I hoped for if, after pouring my heart out, I just get a simple "K." as response. That would make me sad, because I was hoping for compassion and a dialouge dealing with the issue.
But apart from such things, that would probably be totally fine for me.
One behaviour and two very different reactions due to two different people.
As such nuances are often individual, it's probably best to explore what kind of behaviour the other person would feel comfortable with and with which behaviour they don't. Repeat that process with everyone in your life, who you would also like to keep relations to.
That's also related to a thing known as role-behaviour in psychology, which also applies to neurotypicals. When I talk to my superior at work, I behave differently than when I am at home with my wife. Then, I also behave differently with my friends. And among the friends, I learned enough about some, to know what and how I can say something to them and from which topics or phrasings it's probably best to steer away.
That's good advice, but it's also worth noting that my initial strategy was to try to hold of on saying anything at all that could be offensive until I learned what's okay and what's not, but that too ended up offending some people. The reason being that I would get close to people, but they would get closer to me faster than I was getting closer to them due to me still being overly cautious and trying to find the proper things I was allowed to say and do with them. That's partially what this is about. Trying to find the starting line so I know what's not gonna drive people away immediately.
For instance, while it's true a lot of people won't be offended by "K." or proper punctuation, I feel like in most casual contexts, people are much less likely to be offended if I don't do those things, which gives me time to get closer to people and learn more instead of driving a sizable portion away right off the bat.
Another piece of advice this friend gave me was to ask more questions. I always knew that was a good thing to do, but I was always worried people would see me as nosy if I asked the wrong ones. I learned from her that people are generally more happy by me showing interest than they'd be upset by me accidentally asking something personal.
That and the advice I've gotten in this thread has been really helpful so far. Already people are being a lot friendlier toward me, although it's gonna take a bit to change the general public opinion of me.