Exactly! If they hadn't been marginalized by group to start with, they wouldn't need to ask for redress by group. Saying something as facile as "just advocate for everybody" purposely fails to take into account that not everyone is being disenfranchised in the same way or to the same degree. It's pretending that everyone is on the same level playing field - which they demonstrably are not.

It's a big ole defense mechanism to justify keeping the unequal status quo.