I can’t believe anyone is still using and even defending that word as a slur in 2023. It’s been over a decade since the push to remove references to it in federal law and honestly, even 20 years ago I felt seriously uncomfortable with any use of that word in an offhand or derogatory manner, and I didn’t even know about neurodivergence then.
I feel like the culture around usernames on Reddit really enables this kind of behavior, like it’s a game to be as offensive or lewd as possible for some folks there without “technically” breaking the rules. I deleted my account back when the Apollo drama happened and I definitely don’t miss that aspect of the culture. I’m sorry you encountered resistance to bringing this up, because you are right - it is not okay and it hasn’t been okay for years. I suspect a lot of the “just get over it” is folks who wrongly feel like there is no other option but to tolerate this culture in exchange for the ability to communicate and find support online, since the power you have as a user there is pretty much limited to “I’m leaving”.