I think games like Diablo, PoE, Torchlight, Grim Dawn etc all have hardcore mode and there are plenty of glitch/bug deaths. It's a way that you'll build your character to survive those moments.
Are hardcore in a separate instance to the standard players? Or do they share the same world?
If not, they should be. It would be nice to create games and matchmake (even if it's less players overall) that are doing hardcore. Would REALLY make the DZ a high risk zone to go in as well, but would suck to have a softcore player that has nothing to lose kill you.
Some games have PvP modes (like conflict in TD2) where hardcore players can PvP with no death consequence. But keep something like DZ perma death. Would almost be an insane level of hardcore.
Then having leaderboards for stuff on hardcore performance would be nice. Longest character life (in combat would be the best metric for this as you could ask in BoO), most extractions, most rogue kills, etc.
...