Humans are social animals. We are meant to live in small tribes. "Caring" is a survival thing. You have to be able to care about the other members of your tribe or it won't function. Sure, that can be broken down over time with arguments, abuses, personality conflicts, or whatever. But, as a human we then seek out a new "tribe."

Being outcasted is a major issue for us, it drills into the very inner workings of our caveman brain. People without a tribe fall apart pretty fast.

It's like elephants. Outcasted elephants die of loneliness. Baby elephants will die if they are not loved. Humans are the same. You can feed and clothe a baby, but if you don't love it, hug it, play, talk with the baby... the baby will get sick and die. So, caring is important human nature.