You're trying to be PC, but what you're explaining is how they are being dumb.
They have spent years watching it spread. Had it explained multiple times that touching the deceased spreads it. Seen it happen.
Yet still don't change their ways. That is pretty much the definition of stupidity. No understanding of cause and effect, with an unwillingness to learn. That's stupid. You don't have to be nice about everything and spare feelings all the time because you're scared to look hateful or whatever. But if you see people walk up to the face stabbing machine and get stabbed in the face, but then people still keep walking up to it thinking it won't happen to them, even when the big words on the wall say don't walk up here or you'll get stabbed in the face; they're dumb.