I disagree. When I lived with my parents we maintained not only outside dogs, but outside (barn) cats. There are animals out there that are not suited to being 'inside only' pets. Dogs that don't get enough exercise are prone to weight and other health issues, shortening their lives greatly.
Another excellent point is that animals have some pretty kickass tricks used to survive in almost any climate. They go through winter and summer coats, each designed to protect them against the elements. They instinctively burrow or huddle to maintain warmth or coolness.
I believe that it is entirely possible to maintain an outside pet just as well if not better than an inside pet, so long as they are genetically inclined towards that life. I have no problem keeping a german sheperd out of doors, but it would be pretty damn cruel to try that with a greyhound.
And for the record... Sasha (the current barn kitty) can kick your ass, literally. She leaves animals on my parent's doorstep to let them know she's on the job down there.