Different opinions are fine, but letting a dog do its business anywhere and not clearing it up is very anti social. It points to not being a responsible dog owner, like people who let their dogs roam free in the countryside and worry sheep. John lives in sheep country, so probably sees and hears a lot more about it than we do. If you think your dog should be able to poop anywhere without worrying about anyone else or their property, why not let them run free across a field of pregnant sheep and chase a few - small steps in some people’s brains.
As for neighbours, if just being around letting someone know you are watching them works, then it works. I wouldn’t describe that as threatening, just standing up for yourself, but that is my opinion.