Well you gotta make compromises somewhere. The rind of an orange is used for cocktails, but do you make yourself a drink every time you eat one? Or are you so concerned about not wasting edible food that you eat the peel? It's edible but I imagine doing so rather ruins the taste.

Sure you can use 100% of that carrot, pic still has the stem on it too. All edible cookable things. But because I want a specific texture and flavor for my dishes, getting things uniform so they cook evenly is important. Especially if you are following a written recipe because those are crafted with specifically prepared ingredients in mind. It's absolutely not just an aesthetic thing.

Besides, if you peel it correctly we're talking losing maybe 5-10%. That's worth it to me to improve the final product. We're just talking, not trying to lay down cooking laws or anything. But at a certain point ya gotta accept leftover residue at some point.