"Wiping out profiles that you don't know what to do with isn't really helping anything"
What isn't helping anything is when I go to search Joe Blow and I find 4 profiles of him in various states of half documentation. Nobody has merged them because the half documentation doesn't match on them, occasionally conflating a bits and pieces of couple other people with the same name, and the profile "managers," who really don't give a fig about the profile, block all merge attempts; the original creators disappeared years ago so who knows what they really intended; and the "sources" are a bunch of ancestry.com links that haven't worked for 5 years. Because I actually do research, I know Joe Blow's real biography, and I know the common errors, forged sources, potential conflations, etc., but then I have to explain to 4 different people who really could not care less why their profiles are all the same person.
Or I could do what you recommend and let them all sit around for another 5 years, so that nobody knows which profile is really which person.