nutjobs and adventurers often need a hook to hang their mental shit on as they lack the imagination to come up with their own justification for their rape and bloodlust
It's probably quite a high score draw on whether 'religion' has been at the root of the most killing, or whether Nazism, Stalinism, Maoism, drugs cartels, the Shining Path, ETA, Sandanistas, slave traders, Khmer Rouge, Kim Jung Il, Pinochet.......
Well anyway, we've done it before, lots of people choose their own dubious reason for mass slaughter, doesn't excuse it, doesn't make it a legit cause, doesn't make the cited cause actually responsible.