I've seen certain groups referred to elsewhere as Nergal cultists (a W40K reference to the god of disease apparently), and prior to this I thought that was (not inaccurate) hyperbole. Now I'm not even sure its hyperbole.
I don't play WH40K but get the reference. I've been calling then plague rats.
Small minority here but loud.
Can't really say my thoughts or reasonings but the polite version it's the culmination of the post Vietnam era.