When we notice that mixing isn't happening, that means that someone is expending energy excluding others and keeping them from achieving their goals.

Some people also make the related but distinct argument that where that mixing isn't happening within organizations that are particularly well-suited to achieving goals, that means unrepresented communities don't have access to that organization's goal-achieving power, and to the extent that we value equal access to that power by all communities it means we're failing to implement that value, and that all of this is independent of whether anyone is expending energy to exclude anyone, or has any desire or intention to exclude anyone, or whether we notice it.