Yeah, some people are just dense. I have a dog and he does his business in the backyard, but we always clean it up immediately or shortly afterward.
If neighbors can smell it, the dog owners can smell it even more, I can never understand how some dog owners are totally oblivious. It's like when a dog is constantly barking and you mention it to the owners, and they say something like " I didn't hear it" or "I didn't realize it was MY dog barking" WTF?!