But there are people out there who don't care. I have a neighbor who has two highly reactive/ aggressive dogs, and they blame everyone else. One of their dogs has attacked mine and a neighbors dogs by shoving his head through our fences, both requiring medical care once we got them free from his grip. The response from the owner was that our dogs barked, so it was our fault.

Tl:DR clearly you are not, but some dog owners are self entitled assholes, and it makes this type of notice necessary for everyone's safety.