I tend to see it this way...since we made the dog a domestic it's our responsibility to shield them from harm, including elements of the outdoors (sun, cold, snow, ice, parasites, bugs and such)
I agree with a dog having freedom to run and play and explore but do not agree with a dog being outside 24 hours a day.
A dog even that enjoys the elements outside is not nearly as closely examined as one who lives indoors. A dog around us all the time, we're more likely to notice any ailments or troubles.
Thats just my opinion