Not really true -- there are lots of highly trained working and hunting dogs in rural areas. They are not a threat even if they check you out. It's not really reasonable to expect working dogs to be leashed.
That's the way it is around here. Farm dogs are part of the way of life and as long as they aren't vicious, they are accepted. I work on an ambulance and I estimate that on 75% or more of our rural calls we are met in the driveway or yard by one or more dogs. Almost never is it a problem except when they want to jump in the front seat for a ride (grain truck, pickup, ambulance, dogs don't care, just roll down the window). On my bike I've had lots of dogs bark at me from the driveway or the edge of the yard, run along side me in the ditch for a bit, or sometimes even get to be a PITA, but they aren't a big problem, some I greet regularly as I pass by.