Haven't read the whole thread (at least the OP's post though and first page), but I think if a person is walking a dog, I'd almost always 100% agree with making sure there's some level of leash. Not even so much because of other people, but because there's always a risk of an another animal getting aggressive and going after that, and there's no way to pull them away easily to safety.
I've always (along with my family) been lenient in the backyard and in the front when it comes to not having a dog on a leash. Our dog (prior to him passing), we'd try to make sure to bring him up onto the porch in case someone was walking their dogs or someone coming by, unless of course persons show signs of wanting to pet him. Sometimes we'd also board up the front porch so the dog couldn't wander off (Dallas, our old dog, wasn't so much of an issue, but my sister's dog, Daisy, often had a nasty habit wandering a bit too far off).
We unfortunately did have an incident where our dog went up to someone who walked by the house (he loved meeting new people), and the guy literally spit in his face and tried to swat at him. Our dog, which he was always a big baby despite "Acting tough" behind a glass window, backed off kinda notably freaked out. My dad was kinda pissed about that and kinda went after the guy. Like, I get if you don't like dogs, and might be afraid of them, that was on us and we would've immediately apologized, but how he kinda attacked our dog was... Yeah.
But yeah, we were super careful after that incident.
Anyways, I would always keep them on a leash when walking, just so there was no risk for them of potentially being put in harms way (for them or others involved).