"Some ethnogroups are considered in disadvantage" is one way to put it, but it's minimizing it. We're talking about groups that were specifically targeted for their ethnicity: murdered, raped, disenfranchised, and exiled (with no hyperbole).

You can't decimate a group based on ethnicity and then ask why they deserve special treatment for their ethnicity. Further, they're not even getting special treatment- they are having the sovereignty and jurisdiction our _own system_ assigned them validated and reaffirmed after having it unlawfully stolen from them.

You can argue that a tribal government should adopt open, non-ethnocentric policies, but that is their decision to make, not ours.