alt Hacker NewsThe /s thing is the most surefire way to make whatever joke you’re making not funny at all, so I say go ahead and be sarcastic even if not everyone gets it.
And yeah, to your point about the literal interpretation of sarcasm being so absurd people want to correct it, I think you’re right. HN is a particularly pedantic corner of the internet, many of us like to be “right” for whatever reason.
A lot of us are also autistic, and I suspect there's a sizable overlap with the people who like to be right. Though as someone in that overlap, it's less "I want to be the one who brings correctness" and more "I want discussions to only contain accurate facts".
But that aside, it is just simply the case that there are a lot of reasons why sarcasm can fail to land. So you just have to decide whether to risk ruining your joke with a tone indicator, or risk your joke failing to land and someone "correcting" you.