This term isn't only used in K-Dramaland - if you're planning to major in Korean studies you'll have to deal with this as well and it's useful to know what we actually mean when talking about chaebol.
Chaebol is a term used for the business conglomerates. Despite for the heirs of such families sometimes being called 'parachutes' usually dealing with chaebol isn't that easy. They have money and friends. You know, in Germany we'd call that 'Vitamin C' - influential contacts.
That being said, they indeed have a huge influence not only in economics but also politics.
But of course, talking about certain characteristics we see in Korean dramas again and again, that is surely overexaggerated. As well as the amount of chaebol I've seen during the last years.
Usually, in Korean drama, we see conceited, mysophobic and rude male characters. Yes, usually the heirs of such families take over the spotlight and once they realize they can't get anything just by buying it - they tend to freak out or make a 180° turn and change their whole personality. But, oh, well, the latter usually just seems to be a weakness for the female lead.
So how come this kind of character is so irresistible? To be honest I have no idea. That's just my personal opinion but I don't care about their looks if they are rude as hell. They end up as completely loveable characters in the end though after falling for the female lead..
The only case I understand is actually the case of Joo Joong-won and the sun in The Master's Sun because he can actually help her dealing with the ghosts. No matter how bad he treats her, he's the only person who can help her getting rid of the ghosts.
A short collection of chaebol characters in Korean dramas? Yes, sure, here you go:
But to be completely fair, not all of them are bad characters - some are rather charming, a few are willing to give up everything for the person they love and there are a few female chaebol as well.
No matter where you go - I bet you'll find one kind or another of chaebol. But thinking about it logically the amount of families falling into this category in K-Dramaland is really large, even if some of them aren't even mentioned as main characters, they just happen to be there.