That's what I mean. What you said - the turning of a "culturally diverse group of people into one caricatured homogeneous culture based on a degrading Hollywood stereotype" - isn't a problem unless the group in question has been violently subjugated.
I think a key element of cultural appropriation has to be an imbalance in power or some suppression of cultural identity.
In both the cases you've listed you're starting with dominant cultures that haven't been suppressed or forced to change their identity.