Jack Pine,
Welcome to TOTV.
Many people don't realize that in the wild, dogs mark the perimeter of their large territories by leaving urine and feces. Male dogs especially, will save urine for marking, never completely emptying their bladders.
All dogs have "anal glands" which leave a scent on feces just as it leaves the anus. This scent is the reason dogs like to smell each others droppings. The scent gives information about the dog's health, age, gender, and other info. That's also why dogs want to smell each others hind quarters -- to gather information.
Because of the strong instinct to "mark" it is natural for a dog to urinate and defacate during a walk. And like you said, walking gets things moving -- for dogs and humans!
Some people are offended by a dog using their yard, even if you clean it up! So we walk our dogs in the "common areas" rather than walking them down the streets in our neighborhood. Some examples of common areas are the rec centers, grassy areas next to main streets where there are no houses, parks, mail stops, etc. Always pick up droppings with a plastic bag, then take the bag home to be thrown in your own trash.
We've not encountered one person who was upset by our dogs. Quite the opposite -- most people want to greet and pet them and say hello to us. Come see for yourself -- you and your dogs will love it here.