Why conventional weddings are irrational

An $18 dollar dress and hand me down suspenders.

Recently, Michael and I stumbled across "Say Yes to the Dress".  It's one of those reality TV shows that you can't really look away from, but that you look across at your partner while you're watching it and you say "oh yeah: I remember why I love you so much".
I can't get over this show.  Michael, not one for "women's stuff", gets sucked into as well.  It's mesmerizing.  It's the perfect miasma of family drama, money ill-spent, and what little girls (and their mothers, apparently) dream about vis a vis Disneyland princesses.
What the fuck.
The average wedding currently costs around 30k.  That's what some people make in an entire year.  In one other instance would you drop $30,000 in one day?  I would do it if a loved one was held ransom.  I would do it if I had a shit ton of disposable income.  Other than that, you'd have to be pretty illogical to spend what could buy you a very, very nice car which would last you for twenty years, or a down payment on a home.  Or a kick ass, year long honeymoon.  Or a very substantial contribution to your RRSPs so that you don't have to work until you're 67 like an idiot.
What struck Michael, though, was the constant comment that either the bride or the bride's mother wanted a "traditional wedding".
What, pray tell, is a traditional wedding?
What was your parents' wedding like?
What was your grandparents' wedding like?
My mom had never lived with my dad, was very young, wore a borrowed dress and couldn't have cared less about the whole thing.  Super chic, yeah?  All about the flower arrangements and the color schemes.
I think her mother was essentially a war bride and they quite possibly spent their first few nights together crashing with her brother.
What do you thing weddings for the middle class were like in the 1900s?  The 1800s?  How traditional are we talking here?  
And where did this whole "traditional wedding" meme come from?  From the same place that brought you engagement rings, Valentine's Day, and New Years!  And stupid excuse to part you from your hard earned money.  When wedding planners (or stupid brides) say they want a "traditional wedding", I think they're looking at what a traditional wedding is like for Kate and William.
Newsflash: you're not Kate and William.
I don't get the whole shebang.  I don't get the "I've been waiting my whole life for this day" shit.  I don't get the mothers that are so involved in the whole thing.  Or wanting to feel like "a princess".  How does a princess fit into today's society or reality?
Michael says we're in the minority with our thoughts.
I find that kind of scary.