Criticism is perfectly OKAY, but going as far as to hating on them and damaging their reputation is a big NO-NO! 
Have you ever thought about these idols and groups being real humans with real feelings? 
These idols and groups and even groups like KAACHI, ROSEGOLD, and UHSN do not deserve this much backlash. 
Do you want to trigger their feelings and make them feel as if they aren’t good enough? They may seem harmful to you when you listen to their music or hear about them, but they are humans, not robots outside of music. Remember Sulli? Jonghyun? Hara? We lost these three beautiful souls because of the same hate comments y’all give idols and groups. 
We don’t want to lose anymore. 
So please, rethink your words before sending that hate message. Criticism is way better than backlash. 
As a person with mental health issues and had hate comments directed towards me, I was in a horrible state and I was almost gone, until Love Myself by BTS saved me. 
Thank you for reading.