This is a confusion of category vs. example. Cultural appropriation is a type of cultural diffusion in which elements of culture are copied from a minority culture by members of a dominant culture, and these elements are used outside of their original cultural context. It's an overgeneralization to say that that all cultural diffusion is good or bad.
There are both respectful and exploitative ways to adopt traditions from other cultures. It is exploitative when it trivializes the tradition and/or removes vital components for the sake of convenience. It is respectful when it takes on the tradition in a new/interesting way and essentially adds to it.