[somat]

Wow, I have never seen one of those before, and now I need one.

It would have to be a very specific environment, more specific I think than the standard shovel configuration. I think loose dirt, and shifting it or lifting into a wheel barrow. but under those conditions, it would kick ass.

On the subject of shovel mechanical disadvantage, the reason for that is to gain higher velocity so you can fling dirt(or coal or whatever you are flinging) further. And perhaps more importantly to give you mechanical advantage when prying dirt loose when digging a trench.