People that believe their dogs should meet and greet every dog and owner that they come into contact with... reallllly touchy subject with me.
Due to a terrible experience, our Lacy was VERY fearful of other dogs. She didn't react in a negative way towards other dogs... ever. She would shake uncontrollably, and often sit immobilized. Sometimes "scream."
Current dog is a former street dog. Fearful of humans. She isn't a threat to people. She has been "pushed," and has never attempted to bite. She just shuts down. She will lay flat, look in the opposite direction...
anything ...hoping she has become invisible to the person. Even when I TELL people to not pet or talk to her... they still try.
I understand if I told people my dog is not friendly, that would likely stop the meet and greet behavior. I associate the words "not friendly" as a negative thing. The negative behavior is not my dog, it is other dog owners. Leash YOUR dog people! Don't use a retractable leash, where you have little to no control.
Dog issues aside... it is rude to assume every dog and person wants to meet YOUR dog. Use some manners.