[bccdee]

"Intersectionality at an individual level" is poison for a social movement. If everyone lends their support only to movements that benefit them personally, that creates a fragmented ecosystem of niche groups that accomplish nothing. Strength lies in solidarity—in big-tent alliances of disparate groups.

The drawback with a big tent is that small subgroups inside that tent may have their concerns ignored. For instance, black women in early feminist movements were treated poorly, but what were they going to do? Start a schism? That'd be a setback for everyone.

Intersectionality is a second-order tool that protects the interests of smaller sub-groups within a big tent. You're wrong to assume that everyone outside the intersection is "actively repelled." When an environmentalist group says they're anticolonial, feminist, BLM, etc., environmentalists are typically fine with it. Sure, it does turn some people off, but that's a feature, not bug. If your group gets co-opted by people who reject some of these values, it makes it difficult to work together with groups that do focus on issues affecting indigenous people, women, etc.