I doubt it is related to being the younger generation. I think it is more to do with Hacker News not having many "hackers" ;)
As for not knowing eclectic but important bits of history like "2600" or even who "Lawnchair Larry" was, experience takes time, and knowledge takes effort. A good example is that most people don't know all of the available terminal commands available on a UNIX(-ish including MacOS/iOS/Android) system, let alone know the reasoning or history behind all those "funny" command names.
BTW, I always get a giggle out of your HN user name even though the poor disturbed fellow who tied umteen helium balloons to a lawnchair and shutdown airspace of Los Angeles for a few hours eventually committed suicide after receiving his "Honorable Mention" on the Darwin Awards.
Exactly.
Here on HN the confusion is worsened because the definition of "hacker" has shifted from ~"security expert" to ~"technical enterpreuner".
Nothing wrong in redefining terms but we shouldn't be surprised if outside here hacker has another meaning.