What is cultural appropriation and why do people hate it (extremely long details inside)

I have been hearing about this term a lot recently on the Internet, and it is mostly a negative term. But no one seems to agree on the concrete definition of the term. The best I could get from it is that it means borrowing aspects of a culture and using it in a way that encourage harmful stereotypes, especially when it’s done to a culture that was oppressed in the past.

But most of the discussions about cultural appropriation are among American people a lot of them are white. There is virtually no discussion among people in other countries, and especially people in countries where white people are in the minority. So a lot of the discussions are about how some clueless white person takes an aspect of a culture and unwittingly reminds people from other culture of their oppressed past (like writing a story about a Native American god and messing up some details). That’s understandable to me. But in a culture that didn’t experience any of the race issue like America and didn’t have any past action of oppression to another race/culture like my country. In fact, my country should be considered an “oppressed” group by their definition, does the rule still apply? Can people in my country be judged if they don’t have the concept of race in the first place?

And where is the line between insulting a culture and simply enjoying an aspect of a culture? I have some examples of things happening around me that can be “problematic” according to the people hating cultural appropriation:

- When I was in high school, the dreamcatcher (of Native American origin) was insanely popular among people my age. But the only information about its origin that I could get was from a teen magazine, which said very basic things like the dreamcatcher was a Native American charm that helped people get good sleep and dream. And I don’t even think most people my age knew that information. Most of them just thought it was something beautiful to own. And with that a community of people making handmade dreamcatchers was started, and a lot of them were really dedicated to it. So does this count as cultural appropriation?
– Similarly, the omamori (a kind of Japanese charm) is really popular on our online shops. I have read up about it, but most people just don’t really bother to do that. They know that it’s a Japanese charm, and there are several types of it, but they don’t know about deeper details like how it has to be blessed by a Japanese monk or how you are not supposed to open it. Most of the omamori being sold here are of Chinese origin, and they make up their own rules about how to use it like writing your wishes on a paper and stuffing the bag with quartz and dried flowers. I actually really enjoy the design of those charms. So is this cultural appropriation to make charms like that? And am I encouraging cultural appropriation if I like them?
– And lastly, is my attempt at writing a story set in America considered cultural appropriation because I’m not from America?

As an artist it’s a matter that really concerns me lately, seeing how writers/artists are shamed for getting details of other culture wrong and promoting racist stereotypes. I want to be respectful to other cultures, but at the same time there are aspects of other cultures that I really enjoy, from intriguing cloth patterns to a way of life. And “cultural appropriation” isn’t even a thing in my country, so the term is just too abstract for me to fully understand.

What do you think about cultural appropriation?