If you're gonna get married, you gotta have skin in the game. None of this "the couple shared their vows privately before the ceremony" BS. it's supposed to be scary! it's supposed to be vulnerable! it's supposed to bring all the people you invited into your relationship, if only for a moment! and even though i've never gotten married, i've got to imagine that you would feel incredibly close to your partner after both baring your hearts and souls before a room full of people. what a thing to do together!
plus, as a wedding attendee, the reception is always way more fun when everyone's got serotonin coursing through their brains from watching you say really beautiful stuff. a far more important aspect of a good wedding than the hors d'oeurves.