@Dan_Lyons: And to add to what @wildpotato said, I often hear about people who have a kitten or a cat and kids, and the cat scratches the kid, and then the cat gets thrown out or thrown into a basement or hit because of what it did.
OR the cat gets thrown out of the house or punished unjustly because it goes to the bathroom outside of the box or pukes on the floor or any other number of infractions that people who don’t understand cats won’t comprehend.
OR those pet cats go into heat (because the people don’t understand the need for spaying or they can’t afford spaying) and they let the cat out because it won’t shut up, and it comes back pregnant. Then they have kittens of their own, which either are now living outside or given away the way you gave yours away, and the cycle continues. When you adopt a cat from a shelter, they come either spayed or with spaying included in the fee, and they make sure you bring the cat back when it’s old enough so that they try to stem the tide of more unwanted cats and kittens.
When you see a dumpster behind a bank or a food store or restaurant and you see stray cats looking for food, or you move to a house or apartment building and see stray cats hanging around, where do you think those cats came from? They came from people like the ones I described above and @wildpotato described.