They're terminological shell games. It's difficult to tell whether "AAA game" means a popular game, a quality game, or merely a game with a very large budget. It depends on who's using the term and, often, there's a hidden implication that a game which has one of these traits must necessarily have the other two.
It's similarly difficult to tell whether "hardcore" means "challenging", "played online competitively", or "has adult themes like sex and violence". The best working definition I could find based on actual usage is if a game is an FPS, RTS, or MMORPG[0] it's "hardcore", otherwise not; but why not just say FPS, RTS, or MMORPG and not have this hidden value judgement that games which are not in these genres are "softcore"?
[0] Other game categories, like MOBAs and some third-person shooters may now qualify.
It's similarly difficult to tell whether "hardcore" means "challenging", "played online competitively", or "has adult themes like sex and violence". The best working definition I could find based on actual usage is if a game is an FPS, RTS, or MMORPG[0] it's "hardcore", otherwise not; but why not just say FPS, RTS, or MMORPG and not have this hidden value judgement that games which are not in these genres are "softcore"?
[0] Other game categories, like MOBAs and some third-person shooters may now qualify.