Because people who are in love want to get married, like their parents and grandparents and great-grandparents and great-great-parents and [etc] did, not "start

Because people who are in love want to get married, like their parents and grandparents and great-grandparents and great-great-parents and [etc] did, not "start something like company for the holding of joint assets". Getting married is romantic and irrational, and that's why we enjoy doing it.