You can play word games looking for precise definitions of anything. I don't have a clear-cut definition of the word "hacker," but in most places it's clear who is or isn't (I'm definitely not at this point in my life, though I might have been five years ago when I registered here). Yeah, there are some edge cases - maybe someone thinks he's a hacker because he runs Gentoo and knows a little shell scripting but people who contribute substantially to open source projects think he's not - but the vast majority of people clearly are or are not hackers.

Reddit started out like Hacker News, because it was initially best known for being funded/mentored by Paul Graham, so people who were interested in him went there. It mutated into the Reddit we know today - which is why pg felt the need to fork a new community a year or two into reddit's evolution. HN would probably do the same thing given a laissez faire attitude. It's up to HN to decide whether that's a good thing or a bad thing.