I go for walks in my local country park in the summer. ONLY in the parts that dogs must be kept on leads. Because I have a ds who is terrified of dogs. However - 99% of the dog walkers there refuse to leash their dogs when they leave the leash-free area.
My DS2 was already terrified of dogs before we had an incident - now he visibly shakes in terror when he sees them. We were walking through the country park, in the area where dogs should be kept on leashes. We were walking along eating our sandwiches, when a yorkshire terrier ran from seemingly nowhere, jumped up at my DS2, grabbed his sandwich, knocked him over (he has muscle problems, even a Yorkie going full pelt can knock him off balance), had nipped his fingers leaving scrapes on them trying to grab his sandwich, and he had hit his head when he fell.
The owner came sauntering up, and when I complained to her, she said "Well it's only a tiny yorkie, she can't knock him over, he's putting it on, and if he hadn't been waving the sandwich around, it wouldn't have happened - you can't expect a dog not to get hungry when it is on it's walk". I deliberately took my dc for a walk where dogs should be kept on leads, thus I don't give two flying FIGS whether it's only a 'tiny yorkie' or if it is a GSD. NONE of the dogs should be off the leash there - I have MORE right to take my dc on a walk without fear of unleashed dogs barrelling at them for their food etc than the dog does to have a walk OFF it's leash in an area where it is MEANT to be leashed.
I don't CARE how inconvenient it is to the dog owner to have to drive or walk further to get to an area where there aren't dc running around / playing / walking, if the OWNER wants to walk the dog without a lead - the OWNER needs to get off their backsides and find somewhere suitable that WON'T run the risk of affecting other people's enjoyment of the place they are at. Because a LOT of people deliberately pick places to go with their dc that there shouldn't be unleashed dogs. If it is a park where there are dc - KEEP YOUR DOG ON THE LEAD, if you want to let your dog off the lead - THEN FIND SOMEWHERE THAT ISN'T GOING TO BOTHER OTHER PEOPLE.
And no, I am NOT a 'dog-hater', when I did keep dogs, they were either walked on a leash, or I travelled further afield in order to let them off their leash safely. It's called being considerate to other people and UNDERSTANDING that other people will not necessarily see your bundle os fluffy woofyness as cute, other people may see even the smallest, cutest of dogs as scary and menacing, and NOT expect them to be unleashed in public areas.