Non-emotional arguments for why cultural appropriation is a bad thing.
If the case I hazily recall where some clothing manufacturer copyrighted a traditional Navajo pattern actually happened, it’s wrong because it’s someone else’s art.
Ultimately, all arguments are emotional arguments, viz. if nobody felt bad there wouldn’t be any problems. I am perhaps not the best to explain because I think almost all claims of cultural appropriation I’ve heard have been terrible, but there area few things e.g. using a name to refer to something else than the traditional thing – much like the coca cola company might get salty if you cause market place confusion by calling your strawberry based soft drink ‘Coca Cola ’