Why not? Compartments, padding and many are waterproof. My wife has a camera bag with big pastel dots on it that I won in a raffle at a photoclass - when they held it up before drawing the ticket half the room yelled "diaper bag".
Ah, I think the idea is not to carry both cameras and dirty diapers in the same bag, just present a less appealing target to thieves. However the stench of dirty diapers might offer an improved repellent.
A diaper bag is not really designed to carry heavy camera equipment. And with that much weight, I prefer a backpack-style bag that distributes the weight on my shoulders.
You guys can laugh but diaper bag would be a idea thing to carry a camera in, everyone would think you had diapers in it. The last thing you would want is a bag with the name Nikon, Canon on it.