Sucks for us good dog owners that some douches let their little monsters run crazy.
But then again, I don't know if people go home and tell horror stories about seeing me and my dog (who's off-leash in non-designated areas whenever possible). I run by plenty of people with my dog off-leash who tell me I should leash her, I kindly tell them "no thanks, she's fine" and we're gone in less than 5 seconds. No harm. Ever. She has zero interest in anything other than running and noises in the bush. Period. She runs by yapping little sh*t dogs, aggressive dogs, people, everything with no mind to what she's running past unless it's a small creature making rustling sounds in the brush off-trail. One track mind. Nearly a decade of this.
But with all the I'll-sue-McDonalds-for-giving-me-coffee-thats-too-hot type A-holes out there, I'm sure someone will go home and start a thread on some anonymous board about a seven foot 300lb giant sprinting past them yelling obscenities, brushing shoulders and knocking them down while their hell-hound snarled and nipped at them, drawing blood.
I guess my point is that yes, there are plenty of douches that shouldn't let their dogs off-leash out in public. But there are many more douches that overreact to harmless dogs off-leash because they're dipshits. If you went on a run where you yelled at eleven different people about their dogs maybe you should change your running route. Or be significantly less of a douche.