Michael McTeer: FS has multiple parts. You're talking about the collaborative tree. I'm talking about the Genealogies section, which is an archive that anyone can look through but nobody can change, except that the original contributor can delete an uploaded file at any time (and/or upload a different one).
Geni and WikiTree are the other major players in the collaborative tree concept. They're no more suited to unchangeable archiving than FamilySearch's tree.