Hacker News is a social media site for people to talk about (usually) tech-related news. It might be hosted by, and fully run by, a tech startup incubator, but Y Combinator isn't exactly a household name, and the only real indication that this site is related to the incubator is the domain name.
It's pretty easy to come across this site if you're just generally interested in tech stuff (I think everybody I talk to knows exactly what I refer to if I say "the orange site"), and if you're someone who's interested in tech but not particularly plugged into things like the mechanics of startups or business, well, there's a lot on here that's not related to that.
I'm sure if someone came to a site called 'hacker news' and didn't delve deeper past the main content board, then it would be easy to not organically discover what a VC might be.
It's just weird I guess as someone thats been here a while that there are users that don't know the word VC given its history in the VC/tech startup community.
Context matters though. If you're in a place that has always been about baseball and you say "I have to admit I don't know what a pitcher is" it's going to be a bit weird for the regulars.
In this case though I guess it's just hard for me to recognise how much the focus of this site has shifted and that people can come here that seemingly have no interest in startups/tech/vc.
It's not a baseball place. It's equivalent to a sports place and one person won't know what a pitcher is and another won't know what a quarterback is. The scope of HN is quite large and diverse. Then again, even on baseball forums there will be a new person from time to time. It's ok.