“Cultural appropriation” is a connotatively neutral academic term. It’s neither inherently good nor bad. It’s a label for the phenomenon where humans from one culture or subculture (or group of some sort) adopt a cultural “artifact” from another culture or subculture (or group of some sort). I use the word “artifact” very loosely here. It doesn’t have to be something physical. Humans have been doing this for as long as we have existed. This transmission of knowledge, practices, technologies, arts, customs, words, style, etc. between groups is one of the reasons humans have been successful as a species. So it can be a positive, powerful thing in certain contexts.
But in other contexts, it can be negative. I’m certainly not the best person to explain the ways cultural appropriation goes wrong, but here’s my best attempt (it’s going to be very “high level”; if anyone wants examples or a more concrete explanation, there are tons of articles discussing it better, written by people with much more knowledge and authority on the topic than me)—
It’s negative when the appropriation stereotypes the culture or the people the “artifact” originated from; or when it trivializes that culture; or when it distorts or misrepresents that culture; or when it usurps the artifact and its significance, especially when that significance is embedded in the experiences of people from that culture/subculture/group. At its worst, cultural appropriation is done in a way that disrespects or denigrates the culture/subculture that brought about the appropriated “artifact.”... This isn’t supposed to be a comprehensive or authoritative list, just me trying, clumsily, to put some words to some ways that cultural appropriation can be negative.
Trying to find the definitive line between what is positive cultural appropriation and what is negative cultural appropriation—well, it gets complicated quickly, and murky, and in some cases contentious, and I’m not the person to try and define that line, if it exists.
So why in popular discourse does “cultural appropriation” seem so negative? I think it’s probably because the negative examples of cultural appropriation are the ones that spread—through media, through word of mouth, through whatever other way. It’s far more salacious to hear about some hairbrained or asinine or malicious thing somebody does that insults or harms an entire group of people than to hear about the cultural “artifacts” that were appropriated/exchanged neutrally or positively. Consequently, cultural appropriation as portrayed beyond academia is almost entirely negative examples—so of course people start to feel the term itself is connotatively negative.
I think people probably learn the neutral academic definition of cultural appropriation, but hold onto the inherently-negative connotation they were shown in examples. And so they approach everything that fits the neutral definition as if it is inherently negative, or they see things that fit the neutral definition which are clearly not negative and begin to dislike the term “cultural appropriation” itself.
Back to ratchet: I’ve heard the term used. I’m not going to try and decide whether culturally appropriating its use is positive, neutral, or negative. But from how I’ve heard it used, and from the Urban Dictionary link @janbb provided, I don’t think it’s simply a replacement for “wretched” in all the places the word “wretched” might be used. For instance, one of the definitions in the Urban Dictionary includes this—erm—“gem”: Warning! This term is a racial stereotype, sexist fat and slut-shaming speech and may provoke ethnic violence from target. “Wretched,” by contrast, doesn’t carry these sorts of connotations with it. I didn’t see the discussion you had with the other YouTuber, but his concern over your use of the term may have had more to do with this particular word’s connotative meaning than the concept of you appropriating any old slang word.
Sorry this got so long, by the way. Hope it gets at what you were wondering.