Hacker News Reader

Colloquially, it is. See for example BBC’s recent headline “The Viking word hidden in the Declaration of American Independence” (https://www.bbc.com/future/article/20260625-the-ancient-word...)

It's a culture.

If I said a word came from the hacker culture, is it relevant that hacker isn't a language and hackers aren't an ethnic group?

It is (was) a mechanism for language introduction though, to be fair.