From One Green Planet:
Far too often, human prejudice against shelter animals often leads what-could-be amazing companion animals to a death sentence. This sad but true fact means that out of about 3.9 million dogs entering shelters annually, 1.2 million are euthanized … sometimes because negative stereotypes leave them unwanted.
Back in the 20th century, I, like many people, thought adopting from a shelter meant puppy or kitten. I'm sad to say I never really thought about adopting a full grown animal. I had kids and kids wanted a puppy or a kitten. Plus, back then, there were plenty of kittens and puppies to go around in the neighborhood. People believed it was important to allow your female dog or cat to have at least one litter, before spaying and neutering.
I'm happy to say I've changed and I think many people now understand that spaying and neutering is best done when the vet recommends, and not when you, the pet parent, think it should be done. There is no need for your precious pet to have a litter...or to father a litter.