They are noting who they would rather not work with.

That means when they can pick new people for their team(s), they try to pick from those who are not on their shit list.

But if their supervisor tells them to work with X, who happens to be on a no-no list, they won't start a hissy fit. (They might try to influence their higher up to reconsider.)

And in big corps like google it's not too surprising that people with very different worldviews try to stay away from each other.