Why is parents' approval the main conflict in all family drama romances?

I like long family dramas. But I am tired of the same plot being used endlessly. In all the romances, the main issue is that the parents don't approve of marriage. I don't know why this is but in every drama, the disapproving parents are always looking for millionare in-laws. Is it normal in Korea to do so.

And is it acceptable in Korea to disrespect their child's love? Even if they don't like a person as their child's spouse, somethings are not to be said out loud and especially to that person.

yeah that is a thing in korea. Generally you want your kids to marry well and especially marry into a family that is not seen as a "disgrace" as bad as it sounds.  And since it is such a "normalish" thing, it often gets talked about it dramas as well.

And that living with the hubby's/wife family usually after marriage.  I love my family but my home belongs to my hubby me and our kids. My papaw always said when to much extended family lives together to long it causes trouble. Not saying if a family member needs place to stay for month or so to turn em down. But I know the trouble of having em around too long and no thank you. Only family I even let into my home now is mom and stepdad. The rest of em come for dinner and stay week first time then next time screw dinner they walk right in with suitcases, and blankets.