Why Crawl?

When you can get into this much trouble by just rolling across the entire floor to get to what you want, why do you need to crawl?
So, I left her on the floor and went into the kitchen. I didn't realize leaving her on the floor, on the opposite side of the room as her diaper bag would turn into this disaster.

She can get everywhere by rolling and causes me just as much trouble as a crawler would. :D