I say the main reason would be because the parents doesn't want their children to do all the 'hard work' in their lives. In Korea it's harder to get into uni than to get out of it. University is a ticket to a job, kinda, at least braintattooed onto many many parents' heads. So they force their children to keep working, and more work, just so they become a doctor or something, or a lawyer, and never has to do hard work for their lives.
I can tell you, using your brain to work is not always easier than using your physical strength...
There are some parents who do it only for bragging rights too. It's kind of like badly understood 'respect'; "I just raised a world-class doctor, who did you raise".
My parents (both Korean) are kinda different. They want a house alright, but they let me do what I want to do in my career. Even if that'd be playing DDR all day they'd say yes in the end
