I would counter that it’s (or at least should be) a mission driven project.

That mission might be political - but the politics follow from the mission not the other way around.

The mission I’d personally like out of a product that fits Tor’s space is: the ability to unconditionally communicate securely and privately over the public Internet.

Saying that mission is inherently political, sure, you’re going to exclude people who disagree with the mission. That’s kinda the point.

But saying that the narrow politics of that mission means the organization should be broadened to take additional political stances that would exclude people who otherwise would participate in advancing the mission?

I don’t know how that follows.

Projects should only be political in their own field. For example, the FSF should be political in copyright and patent matters, but not military or entitlement spending matters.