TBF to John, purposefully failing high end raids to force a dungeon break and murder whole cities/states/countries is a fairly ludicrous concept. There's always a PK-er guild in these type of apocalyptic system stories that also wants the world to burn, which I never really understand (not counting the SAO types, where they are trapped in a game). It usually makes for decent battles and arcs, but at the same time, it's a fairly consistent yet mostly unbelievable setup.
PK-ing, taking down the 'adventurer guild' enforcing civilized rules, taking out the big guilds to enable a take over, all of those things I can believe. But not a highly functional, deep planning, shadow guild that just wants to cause everyone to die (presumably except them). If they were traitors to humanity and in communication with whatever is causing the apocalypse, I could see that. But they almost never are. They are just functional nutbags.