Near my house, there are some renovations going on. Outside of the apartments being renovated, they reserved a spot where large pieces of furniture and garbage could be dumped. One morning, I noticed that they removed the spot and a sign was placed that prohibited leaving trash.
This went pretty well for a couple of days. But after a short while, I noticed a couple of items. When I came back from work, the place was filled with garbage.
It reminded me of the broken windows theory: where one thing leads to another. A piece of graffiti turns a subway into a violent place. As soon as there is one broken item, more stuff will be broken.
This is why you and I need to take good care. Clean up after you. Write good code. If you agreed on something, follow trough. Value integrity. Because reality is: you have followers. So if you want them to be better, raise the bar and set a great example.
Fix the broken windows before lots of them are appearing all around you.