Nigerians Boycotting District 9...hmmm I wonder why...

I'm not Nigerian or anything but I understand why they are protesting District 9. That movie made them look like criminals, thugs, schysters, canibals, and they were having interspecies relations. I would not have enjoyed if I were them. My question, is why weren't the aliens having relations with the white South Africans? Hmmm. Were they too pure for that?