In the first place, so much of the aesthetic is based on gangster culture. Black gangster culture specifically. Based off of the actual real problem of black violent gang culture . How can that be considered good in any way?. And the music itself is low class, simplistic and has no real melody. i don't know why anyone likes it to be honest.
And White or Asian people copying it are worshipping black gangster culture because so much of hiphop and rap is based around that. Just look at the lyrics and music videos and what the "singers" wear and how they conduct themselves. All the tattoos , too many metal piercings, stupid amounts of jewelry (again , its based off of materialistic gang culture) just all around uglyness , rude gestures and behaviors, trashy . In general its all just vulgar.
And why is something that was invented decades ago always promoted like its "cool and modern"?
Initially, it was rooted in political messaging and long form vocal performance, also catapulting the use of turntables as an instrument, but it started to devolve right at the end of the 80s, as it turned into promoting ghetto culture by the big labels. The whole decade of the 90s is what soured it, first making it about violence and drugs, then proceeding to sexual denigration (really started with Public Enemy but it became more commonplace later).
Popularization was going in full-swing around the New Millennium as "artists" like Eminem started to cement its popularity with Whites, and the nu-metal sub-genre of hard rock had incorporated it into vocal performance and rhythms, starting with Limp Bizkit (maybe Korn did it first?). Once the music industry catches whiff of something to be used as a cultural wedge, they put it on full-blast (ghetto rap, nu-metal, Taylor Swift, Jelly Roll).
Yeah, gangster rap is terrible for the nation and a lot of the rap genre has produced trash, although some rap/hip hop is tolerable. You can hear the distinction between the era of Sugar Hill Gang to Run D.M.C., LL Cool J and Beastie Boys. Then Public Enemy and N.W.A. Then Wu-tang Clan, 2pac, Notorious B.I.G and Common. Then Eminem, Kanye West, MF Doom, etc and at that point there's various subjects they focus on.
I've never heard of this, although I don't listen to critics or the Industry anymore. I do remember in the 00s when it was trying to be seen as "cool and modern", as it was fusing with other genres, but it hit it's "artistic" peak with critics around 2010 (Kanye West / Kendrick Lamar). I don't think it's any different than Current Year music trying to promote itself as cool and modern when most genres and pop music haven't evolved in over a decade. Country pop music is trying to be "cool and modern" now too