Yeah, we should do everything the way we did 40 years ago, and this issue has little to do with tree huggers. Dumping your germs and food on the ground would be better than nothing, but since we have an alternative, not dumping correctly is just being lazy.
But, if it really isn’t an issue. Feel free to put a sign up in your front yard to encourage people to dump their grey water in your front yard. Report back how that works for you. :D