Responses
Because he's power hungry. And wants an heir for his company.
Some parents are absolute control freaks. Others are such losers that they can't achieve anything on their own and so live vicariously through their children by forcing their kids to do all the things they themselves can't.
Why did his daughter matter for Mr. Gu anyway? All he ever did to her was forcing her to marry a man she doesn't love, cage her and bossing her around. Even demand a child from her loveless marriage. He should just let her go and be happy, unless he's a heartless douchebag everyone keep calling him as.