And to answer the OP:
I think that it is important to address the needs of the animal which you are considering. For a horse, this includes certain care and a certain sized enclosure. You can't just stick a horse in a small yard and never care for its hooves etc. A goat would require very strong, secure fencing and regular hoof care. I would not be allowed to just go buy a goat and let it loose outside, knowing that it will come around a couple of times per day for milking and grain. My neighbors really wouldn't be happy with me.
So why would I do that with a cat?
I actually used to know of someone who loved guinea pigs but felt this 'animals must roam' sentiment. They would buy several guinea pigs and let them roam free in the yard to blissfully graze in the lawn and romp under the deck. I live in the mountains near Tahoe (subfreezing winters). Guinea pigs do not survive in the ice and snow, so this person would just buy new ones each year
rather than keep their pets in cages or some kind of indoor enclosure.
My landlord feels this way about her dogs. I've posted here about the lovely results of her free roaming dogs.
What exactly is it about cats that makes people think that they alone, of all possible pets, must be allowed to roam freely? Their independence mustn't be curtailed, such a thing is terribly cruel.
I don't feel that I have the room in my life at the moment for a 100% indoor cat. Thus I don't have a cat. Simple.
ETA: If someone feels the need to own a pet which can roam as it likes, I really think that they should investigate animals which are actually native to the ecosystem. Squirrels, opossums, chipmunks, skunks are possibilities. These are adapted to North American conditions and therefore are not likely to decimate more than their fair share of the habitat (as cats do).