As a longtime kpop fan, I still don’t understand why kpop fans treat their idols either like babies or like some kind of bad b*tch.

angsty teens will act like angsty teens. and when they become adults... some don't grow out of it.

Because the loud ones are the craziest ones

The normal ones are living life(9-5 Jobs etc..)

How to explain it ?
In the sky you only see with your eyes one type of star, but not the invisible ones which out-number them by many magnitude factors. For one visible star you have thousands you need an instrument to spot. That's the same with social media recommendations, most visible reactions are not the normal ones.

parasocial relationships be parasocialling

Because they don’t view them as real people but as characters and make up their own narrative about them in their heads like they do with anime/movie characters. It’s also why there’s so little room for nuance… everything must be to the extreme.

I somehow agree, you don't often see fans that see the idols as regular people just doing their job, usually people have extreme reactions and like to overreact.

I guess it's because those fans are more vocal online and it's the majority?

I know everyone is different and can act the way the want, as long as it's not harmful, but I've always found it funny when I saw teenagers babying the idols who sometimes are much older than them.

Personally, I really like seeing behind the scenes videos that show a more normal side of the idols compared to what they show on stage. They just happen to be popular and work in such industry that paints them as perfect, but behind that most of them appear as normal and humble people, like you and I, just doing their work.