https://xkcd.com/1053/ sometimes it is nice to bask in the glow of another person's TIL. There is a simple joy to it like the smell of freshly-cut grass.
yes and -- informing someone that the term is more widely used than they might otherwise have known is indeed useful
Yes to your second sentence. I read kube-system's comment in good faith. It was providing community context.
I once got excited about what I thought was a cool idea (I can't remember what it was, but something along the lines of "black swan theory"). I didn't know how established it was, so I started inserting it in talks with the assumption people didn't already know about it. I belabored its definition and dwelled on it, when in fact people in academic communities had already discussed it in depth, and have moved on to other ideas. No one said anything, but no one engaged with me after my talks and I wondered why.
Looking back, I wished someone had nudged me and explained the context of that idea in those communities. I must have come across as a pseudointellectual (in that particular context). Feedback matters and is helpful when given kindly.
(on "regulatory capture" specifically, I admit I had not heard the term until about a year ago when it came up several times on Tyler Cowen's blog and on HN)