It's partly anthropological. Our brains have grown larger, we've grown smarter, we've learned to acquire our food and other necessities without spending all day hunting and gathering, so we have time to spend thinking, so we have gradually become ideological. Now we value taking a stand, often more than being kind to people. That would be OK if our stands were always in the best interests of society as a whole, but they usually aren't. We're still selfish creatures, and we don't want anybody telling us to be nice.
The American political scene this year is quite an unpleasant example of this misplaced idealization of conviction. Master salesman that he is, Trump has convinced millions that insults, slander, bigotry, racism, sexism, and alienating other countries is preferable over being respectful. Kindness is perceived as weakness.
I was accused, years ago, of being too interested in having people like me. This, I was told, was a serious character flaw and the biggest obstacle in my personal relationships. I didn't know how to respond, mostly because I don't give a hoot what people think of me. But accuse me of being kind, and I'll consider myself both honored and successful.
Who would have ever thought that mankind would scoff at caring about one another, being gentle, forgiving, understanding, generous, patient, and loving? That we would instead embrace extremism, drama, sensationalism, dogma, taking a stand no matter how misguided, salesmanship, visibility, and the ability to pull the wool over other people's eyes? Worst of all, we see people who amass fortunes, even at the expense of the society as a whole, as winners, better, smarter, people to be admired. We want what they have. We couldn't be more wrong.
Anthropological or not, the evolution of intelligence is not serving us if our compassion doesn't evolve along with it.