A huge number of people are extremely eager to tell you their long-winded justification on why some group of people should be exterminated.
I don't see how there's any value in trying to understand that because the division is built right into the premise.
Which is also what we need to stick it to the man. They want us to fight and bicker and be divided into camps and never agree on anything. That’s how they can keep doing whatever they want. Even better if we convince each other that talking about this stuff is taboo and unproductive.
Remember: A populace than can work together is a scary populace, if you’re in power.