Why do people want their children to get married even though they don't have a good marriage life?
It is weird to me too, I think people should stop thinking that marriage is a must. You can survive without getting married and even have a better life compared to someone who is in a toxic or messed up marriage. For example those women who get married as the third or second wife. You can't be happy living in such a marriage or family since you won't feel the affection from your partner.
I live in India and here it's so mandatory to get married by 25. If by fault you are 30 are still aren't married then according to the society you might have some default and that is why you are not being able to get married or something like that.
People want their children to get married because they may want them to experience the same joy they had when they first got married. Despite the fact that they may not have a good marriage life, they may still value the idea of marriage and want their children to have the same opportunity to experience it.