Perhaps by watching lots of home videos on the internet or TV of people hauling massive tiered wedding cakes around, only to drop them or for a tier to give out and the whole thing to fall over?

As pretty and traditional as they are, they aren't nearly as practical to cut for a large crowd, especially once it's fallen on the ground, and nothing tops off the single largest event you'll host and pay for in your life like disappointing all of your guests.