I mean a lot of idols (or rather, their management companies) try to appeal to incels, so if anything, they're the reason why these idols are so famous in the first place.

Pff I haven't got laid in like 10 years but I don't make it anyone else's issue.

Happening right now with Yuuko Yurei, she stopped doing girlfriend experience content and switched to vlogs and stuff, she's plummetting. Very hard to leave after you captivated this audience, since the people that don't like the former content already left a long time ago.

The only thing that makes US crazies different is the easier access to firearms.

This may come as a shock, but shitty and crazy people exist everywhere. Either Japan, Korea, or both have had stabbings at events where people pay for tickets to shake hands with some of the idols. The difference is that, at least speaking for Japan, firearms licensing and ownership is very strict so someone's not going to go shooting up a place. The guy who assassinated former PM Abe basically built a blunderbuss out of hardware parts and electronics to do it and it was a single-shot.

Mental illness is not confined to one country.

This is specifically why the apology exists. It’s to keep her safe and hopefully with a career still.