Case:
Like some nugu idol does a cover of some popular group, and he/she does a good job.
Then some stans of covered popular group come in and say wow he/she did a good job I thought it was "A" idol, wow he/she sounds like "A" idol.
Then other stans get triggered over that and say no he/she doesn't sound like "A", and drag that idol saying u will never be "A", there's only one "A", u sound average, u are terrible, u should disband etc.
In this case the nugu idol who covered the song has like no wrong but ended up hated and harassed by toxic kpop stans. Like how much u do a good job in covering u will never win. That's why it's so hard to be an idol from nugu/small company. There's always this triggered toxic popular group stans that will harass you and destroy you whenever u get some attention.