Millennials are all about menu-driven prioritization in an age of economic scarcity. It's not that they don't want to get married. (The vast majority do, and that share has not declined appreciably over the decades.) It's just that they believe that they need to get everything else "in place" beforehand. Whereas young Boomers focused on "the now," regardless of the probable consequences, Millennials are regrowing behavioral habits based on delayed gratification. Go talk to Boomers about young couples trading FICO scores on their second or third date. Every one of them will shake their head in utter disbelief.