The typical North American wedding is just bursting with meaningful traditions--if you know where to look. Take bridesmaids' dresses. They're not just evil looking; they're evil-repellent.
If you've ever wondered why bridesmaids all dress the same, it's because Roman law required ten witnesses to make a wedding legal. Several of these witnesses dressed up exactly like the bride and groom, to confound any malevolent forces who might show up uninvited. Europeans followed a similar tradition, and later bridesmaids and groomsmen sometimes did have to defend the happy couple against real-life thugs and warriors (see Lefty loosey, righty ... bridey? below).
This does not explain why bridesmaids' dresses are almost always ugly, though. My Internet Magic only goes so far.