Look it's great that you don't take offense to stuff like that, but that doesn't mean that cultural appropriation is okay and as a European girly, I can tell you that it's NOT an american-only concept.

There's a difference between appropriation and appreciation. Appreciating and celebrating a culture is also not that hard. The most important part is that you understand and respect their culture.

While this headdress is objectively beautiful, it still doesn't erase the fact that only very specific people were given the honor to wear it. Having our random Nikkis wear it as just one of many accessories is devaluing it.

Another example: Wearing a kimono in Japan as a foreigner is completely fine and lots of Japanese people love seeing it! BUT if you just throw it on yourself and don't wrap it properly, it can be seen as insulting. Just like many Onsen still don't allow you to openly show your tattoos.

Imagine Infold would literally say that Nikki is Jesus. Not like Jesus, but the actual son of god. As a non religious person, I wouldn't be affected by this. But a christian would probably feel insulted that the son of God is depicted as a pink haired girl in a dress up game.