So, I bet some of you guys might laugh at my question. But I'm serious: Why exactly do we need catholes?

I mean, of course nobody wants both sides of a trail totally messed up with human shit, I get that. But that's not what catholes are about. Animals shit all over the woods without digging holes, don't they? And animals shit near water, some even IN the fucking water. So why are we humans the only animals that feel the need to bury their shit a certain distance away from water sources and trails? The wikipedia article even suggests smearing your shit over a rock or throwing it in the fire. I feel like I'm missing some point here, please explain this to me.