Because you are also not perfect. I've witnessed a lot of anti-women hate from this so called "woke" generation, which is in reality just a rebranded version of the patriarchy for the modern era. They aren't burning women at the stake now but they want to kill their reputation and destroy their careers. To this day Irene gets hate daily for her controversy which she apologized and was forgiven. Yuqi was hated to hell and back and even apologized FOR SOMETHING SHE DIDN'T EVEN DO. Because of a mistranslation a subber made. Personal attacks against women who make any kind of 'problematic' mistake in public, whether their action, inaction or words, occur habitually. Even if they apologized, their attackers don't care and will continue to bash them relentlessly.
Yet an 'oppa' would have to do something incredibly vile or criminal for many of his fans to stop shielding him, but even then there are still fans supporting a child rapist or woman beater, telling him how much they love him.
I know many people will say, "i don't care, I'll hate on whoever i want", but if so you'll have no right to complain when it's your turned to be fucked over by society.