I know mys probably already got it in their head that it's all about jealousy and bitterness. Which yeah some of it probably is or at the very least are a symptom born from the actual reason.
The actual reason?
Aespa's "success" in the West comes across as very performative. Meaning, SM is media playing them too hard to appear as if they are on the same level as BTS and Blackpink, which if you actually look at stats, makes people feel very cringe toward them.
SM seems to be checking off everything BTS and Blackpink did in the west as if to say "look, they are on the same level"
When in reality, it you look at streaming, Instagram followers, YouTube views etc. Aespa doesn't even have a quarter of the same level of achievements.
So far, the only thing they can boast are album sales, but as far as most are concerned album sales are becomming irrelevant rather quickly due to cheap digipacks and cbars bulk buying. It really is hard to think most of these albums are going to be going to actual people and won't either be donated or shipped off to some dump.
And I think, it really wouldn't have been so bad had Aespa actually had the appeal to justify all the push SM is giving them, but a large majority of people don't see it.
Even though people used to hate on BTS, they at least had music that majority of people included haters couldn't deny was good. For Blackpink, even though people thought they weren't strong performers, they eventually proved they could indeed put on a good performance.
But for all of Aespa's push, there doesn't seem to be an upside that would otherwise balance it out for most people. I would go into detail, but I feel like if I start picking them out mods might mistake this thread as a hate thread or whatever.
I honestly just wanted to dissect what it was that was causing this adverse reaction with Aespa to most kpop fans.
Tldr: to a vast majority of the Kpop fandom Aespa come across like a group of nepotism kids parading around their parent's connections without having earned anything on their own merits and lacking self-awareness of this fact.

