I hate people sometimes! Mine is TOO friendly with strangers, gets all excited and stops attending to me, which is counter-productive because we're out walking, in part, to train.
Honest to Pete, our society really is aware that they are not to touch a working service dog. Now, I want to be very clear... I NEVER claim my dog is a service dog. I NEVER avail myself any of the privileges we accord service dogs. I have a disabled sister and that sort of thing honks me off. Very immoral thing to do.
BUT... I bought a harness exactly like a service dog, only it says... "In Training". Which is the truth. This has enabled me to walk around just about anywhere dogs are allowed and not have people get in our space.
I wish people would get that our dogs are not there to give you warm fuzzies. (Exception being therapy dogs on the job.)
Owners do not have to allow people to pet their dogs.
So that's my opinion for what it's worth.