Because, Isabella Merced and her friends by had received death treats by Tankies, American Indian Movement, and the Far Left, just because Spirit Untamed "ruined the Pro-Indigenous message". But I just think that they are all biased, because American Indian Movement (AIM) and Tankies support various dictators (Especially Right Wing to Far Right ones) worldwide.
Also the hate for Isabella Merced is unneeded, because she herself is Mestizo, a mixture of European Spanish and Indigenous.