Fenders not only keep the spray off your face and back, but also keep your feet drier. We can't emphasize how important dry feet are to happy commuting. Arriving at your destination without being fully drenched maters too. For light showers riding with a rain coat and fenders usually means you don't need rain pants. They also keep your bike cleaner - not just cosmetically, but components like the drivetrain and brakes wear out a lot faster when they have water and road grime on them.