I care about genealogy! Of course, it's debatable if I'm considered "young" since I'm 30. I think maybe there would be privacy issues and personality rights to photographs that would get in the way of such a big family tree.
Not to mention a security issue as well since most financial institutions ask for your mother's maiden name as a security question.
There's no open source genealogy programmers because the young nerds that do open source dont care about genealogy.