“I don’t know why so many have trouble grasping just how insane these twelvers really are.”
Yes, but such a failure can be extraordinarily convenient if you want to believe that you can avoid confronting those twelvers. If your position is that Iran can be ‘deterred’, then admitting that they are religious extremists who believe their mission is to wash the world in blood and usher in the rule of the 12th Iman is rather inconvenient.