I guess we'll agree to disagree on this subject.
The only thing I'd like to clarify is that I am not saying an older person doesn't have a right to own a young puppy only that especially in rescue the goal is to find a "forever" home and I (speaking for myself & other in rescue) do our best to ensure a dog's future being with one "final" owner...that's all.
You're very right that there are no guarantee's that even the youngest pet owners might not outlive their pets. However, choosing to ignore the greater possibility is not one I am willing to risk when placing a rescue.
All the best to you & Mindy!