(What on earth would cause them to do something so stupid.)
I’m sure you already know but it is not from Earth. It is from principalities and powers (fallen angels) in the spiritual realms, trying to destroy everything God has ordained. Ephesians 6:12.
There is also that spirit of antichrist preparing the way for Satan’s anti-messiah.
Matthew 18:6
King James Version
6 But whoso shall offend one of these little ones which believe in me, it were better for him that a millstone were hanged about his neck, and that he were drowned in the depth of the sea.
https://www.biblegateway.com/passage/?search=Matthew%2018%3A6&version=KJV
Ephesians 6:12
King James Version
12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.