There are jurisdictions that have maintained some form of vows in their wedding ceremonies. Why? The immediate answer would be Latinization, but this is not exactly true. Historically the old world countries where the vows insinuated themselves into the wedding ceremony did so because of government mandate. Why do people continue to keep vows in their ceremonies? Simply put it's hard to take something out of a ceremony once added, it's hard to imagine doing a wedding unlike what your mother/grandmother did, and really the clergy need to make the change.
(AFR) - Fr. Stephen notes that in an Orthodox wedding, there are no wedding vows. This stands in stark contrast to the central place vows hold in Western tradition. He suggests that the West has come to think of marriage as a "contract" between two people while the Orthodox Church thinks of it as a "union." The difference is important.