A lot of people also believe that their way is "the one true path" and don't understand the concept of "different strokes for different folks." That's heavily compounded when you live your life according to a book written hundreds of years ago by tyrants who needed a way to control commoners through mind control and guilt tactics, because earning their support by treating them fairly and giving them what they needed was way too much work.
Sadly, there are far too many people who just aren't happy with their lives. And too many of them are like my late MIL: "If I can't be happy, I don't see why anyone else should."
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker