[T.B. Yoits]

It’s because their beliefs are more of a virtue signal than an actual belief based on data and reality. When you disagree with them, you are calling them a bad person.

This.

They have no self identity and are terrified of being ostracized by the like-minded group they're among. Without that group, they have nothing.

[T.B. Yoits]

“Reasoning will never make a man correct an ill opinion, which by reasoning he never acquired.” - Jonathan Swift ‘Letter to a Young Clergyman’ - 1720