I disagree. Have you seen what happens to paint at the bottom of door panels and fenders over time when you DON’T have mud guards? I say its a worthwhile tradeoff (looks vs. function) to have them in place.
I’ve thought about it, and have seen many pics of cars with the flaps off. Those cars just look like they are riding like dumptrucks. Only looks good if your car is laying on the floor, if you know what i mean.