Leftism is dogmatic by nature. Its ideologies necessarily require forcing societal change based on theoretical frameworks for social organization that can never and will never emerge organically. They need total ideological compliance for their insanity to have even a chance of working. The mere fact that people exist who disagree with them is a threat to their entire belief system and moral framework. They know it, and they resent it.

For conservatives, who value the traditions and institutions that our society has already developed and is built around, the proof of our beliefs is self-evident. We value what already works because it works, and so we don't feel the same all-encompassing need to fear or malign ideological dissidents. I would argue that we might want to do a bit more of that, given the shitty job we've done of safeguarding our traditions so far.