I've always thought that the main reason Jin Yi was so desperate in her loves is because Baek-Moo told her they could never be first and that she could never live without them, and when you're that in love with art (which will almost always have a competitive edge, especially that kind) you almost can't help but rise to the challenge. Then, of course, she had the example of her mother and the man who loved her.

BTW, I hope you don't mind, but I friended you.