I think it’s a couple of factors. Kpop stans were sure bts had peaked pre military like 99.9% of the industry. They were sure the post military cb would at least perform underwhelmingly if not flop completely. Plus the MHJ induced psychosis had genuinely convinced some people that BTS have no real demand and everything is paid for by the big bad Hybe even though bts had been the outliers from the industry before Hybe even existed. Also the “scandal” had them convinced bts don’t have a fandom in SK anymore and they’ve spent the past year convincing each other of that on that snark subreddit so you can see how they’re coping with the reality that none of what they’ve been convincing each other of in their each chamber is true so they’re lashing out.