Just a product of people having an overconfidence in themselves being right (and therefore good) while those that disagree are wrong (and therefore wrong).
The irony is that the most batshit insane MAGAs have the same thought process. Liberal tears and all that.
This is a “conservative tears” kind of thing. It’s a “they take the low road, we also take the low road” kind of strategy which only gives credence to the usually fallacious “both sides” arguments.
General lack of critical thinking skills. If you want a tolerant society, actively disrespecting the beliefs of others probably isn’t the best way to go about it.