No. Simpler (for you) not to consider these things :)
Cultural interchange is inevitable yes, but is its effect on the human condition negligible? No. So why not talk about it.
Also they didn't appropriate it because it was fucking Germanic to begin with.
You can't prove things like that, so why do you believe this stuff? Why do you present it as fact?
So? All culture is subjective. What is offensive in one culture can have a completely different meaning in other cultures [0]. Cultures are the result of human opinions and by definition that makes them subjective.
Human interpretation of actions, symbols, words, or what have you that defines is a culture is the direct result of a group of peoples' collective opinions given to those actions, symbols, words, or what have you. Cultural appropriation is taking something away from a culture and trying to give it a new meaning, particularly with a meaning that the original group dislikes.
Which is little more than "Our opinion on this thing came before your opinion. You're being rude by ignoring our opinion on this thing and we don't like that."
For the people that know that you cannot own a culture and there is no central authority which to determine how it can be used.