On the other hand, when I have to go, I don't want to spend time looking for a stick sturdy enough to dig a hole In dry ground, or ground soft enough to dig my heel into. My qiwiz trowel weighs about 16 grams, and is a multi use tool. I've used it to stir hot coals, a more sturdy stake in soft/sandy ground, a tool to pick up and examine random bugs and spiders, as well as just to dig when needed (not just catholes).
I just think this is one piece of equipment that a responsible trail hiker will have (or at least something that serves the given purpose readily available). I have also heard of rangers checking in some national parks as well, to make sure hikers are carrying trowels. After stepping in a few unburied piles, I am glad they are checking.