This depends on a person. Some people ride only in fair weather in shorts and find them redundant. Others always carry a strap to put around the leg of their pants. Others ride in all kinds of weather and circumstances and will get their clothes stained without a guard. I belong to the last group and have a chainguard on every bike. I also put a chainguard on any bike I outfit for somebody as I fear that they may get put off from biking if they get stained. Obviously the chainguards come in different forms. Some are minimal but effective enough. Other are bulky.