Doom is a game that attracts edgelords because the very subject matter involves rock music, demonic imagery, lots of blood and gore, and lots of violent ways to kill stuff.
I don't need to explain why that's an edgelord sperg magnet, do I?
Interesting. I read most of what went down when that happened, and it looked to me like he utterly refused to apologize since he was being sarcastic to begin with, everyone else was pissing themselves over "oh shit, what happens if it gets out that someone in the Doom community wound up dead because we let another member egg them on to suicide", Mark didn't agree and thought they were being babies and refused to back down, and it all snowballed from there until he got thrown out.
As I pointed out earlier, the Doom community really is gunshy of encouraging edgelords since those types make bad modders and for even worse press (Columbine did the Doom community no favors and they had to live down false rumors about them encouraging other violent edgy assholes since), so it sounds like they assumed Mark was going Doomguy on them (being an unironic edgelord in dead seriousness), emotion trumped logic, and he wound up tossed out because he didn't see why they were reacting so badly.
Unlike Doomguy, who is an unironic edgy dumbass, sounds like Mark just didn't pick up on the fact no one else wasn't in on the joke (and didn't see what was supposed to be funny to start with) until too late, and by that time they declared him haram.
