Eh, I know a few people here who would disagree with you still on the level of harm. One of them is an artist.
Also, some people refuse to drop gum wrappers on the sidewalk because they know that eventually, that trash is going to end up somewhere and it's going to have to be cleaned. Jaywalking can result in dead pedestrians, forgetting to put your blinker on can result in an accident when someone believes that you're not going to turn, and U-turns can also result in car accidents -- or at the very least both of the previous ones result in pissing off lots of other drivers who have now missed their one chance to turn and have to sit there for several more minutes waiting for the next opportunity.