You actually raise quite a big thing here. I don't think it specifically comes from Hispanic Youtubers, i felt that a lot from many people. It can almost be painful to note that most non-korean or non-asian publics have a very narrow-minded caricatural vision of k-pop. They seem to believe there is no diversity or true creativity, as if these songs and performances were the art of robots lol. However i think we have to considerate that Labels do participate in spreading this "bland" image. We have a true example of that trend with BTS : here was a group with powerful songs bringing up rebellion, youth problems, difficulties in finding our path in such an individualist and capitalist society, sexism, depression... and now that they've reached the American market it's very conventionnal, fun and cool and stuff but so... formulaic ? This is a will from the companies. To everyone who's not into K-pop, all the songs, mvs and even idols are the same, like copies or clones, and to them it's weird and funny (plus totally deshumanizing...)
But even if this is deliberate, Youtubers/producers or just music enthusiasts should make the effort to go deeper. Many american songs are conventional and trendy af lol. At one point we'll have to adress the possible issue of racism in such a treatment. There is some kind of paternalism idk, from American artists, to see Korean idols like cute brilliant dolls while they are true, grown up artists and performers. It's irritating.
As you pointed out, at one point this is a choice : you go to the surface and express a superficial opinion, or you try to understand if there is something else (something more !) behind the curtain. We did it, why can't they ?
Thanks for bringing up the subject anyways !