I just find it weird, like astrology or ultras, idk.

I think you accidentally hit the nail on the head there. When you and I feel proud of our features, we are proud over the features themselves- not proud of identifying as part of the group of “all blue eyed people” or “all weird hair quirk people”.

It’s the affiliation with, to a greater or lesser extent, some group, and that group’s interests:

As a proud blue-eyed person, I couldn’t care less about what all other blue-eyed persons think, and unless there’d be fewer than a thousand left of us I couldn’t even conceive of any collective agenda such a group might have had.

As a proud black person, I would be highly motivated to care about and affiliate with all other black persons, because they would share experiences with me, and to a great extent negative or hateful.

As a proud homosexual, I would likewise affiliate with others of my kind or who have had similar experiences.

Even as a proud Ultras member, I can see how you would affiliate like so, even if the reason for it would rest on an artificial division between some arbitrary group- belonging to Ultras is not a physical trait, it’s made up, but there at least is some rationale.

As a proud white person? If white people were selectively persecuted, I sure as hell would affiliate with them, but they aren’t.