In my experience, when I have told an NT person that I am #autistic, they tend to take it to mean one of two things:
1. They think if I am self-aware enough to know I'm autistic so that I could tell them about it, that implies I know the difference between autistic and normal behavior, so I can just do the normal thing, because that's all it takes, knowing what the normal thing is. They think I'm informing them that I've got it handled, so they can just carry on as usual without any adjustments. Maybe they think I'm bragging or asking them to be impressed? Who knows.
2. They think I am informing them of an insurmountable barrier to communication, and conclude it will be too hard to have a relationship (of whatever kind), so there's no point in trying.
The frustrating thing is that they don't realize there is a third option: They could meet us halfway. They could learn to do their part in bridging the #DoubleEmpathyProblem communication gap. They could cut us a little slack when we unintentionally mess up and break one of their mysterious social rules that are impossible for us to learn, because part of the rules is that they always lie about what the rules really are. They could try to understand that we see the world differently than they do, that the way we see things is just as valid as theirs, and we shouldn't have to do all the work to bridge the communication gap without any help from them.
And beyond frustrating, they appear to think the way to support me is to "help" me adapt to NT social norms. They tell me what I'm doing is wrong, even without me asking. They "guide" me toward NT standard behavior, which usually feels like bullying because then they punish me when I don't conform. It feels like everyone thinks it's their job to be an ABA therapist and gently torture me into normality.
There are, thankfully, some people who I'm close enough to that I can lead them to the third option. But that's always hit-or-miss, and is never easy. I'm really grateful for the handful of people who really do accept me, and even if they don't understand me all the time, they cut me some slack for not being able to perform NT.