User blog comment:Dopp/New Profile Design Now Live Across All Wikis/@comment-876022-20110818192021/@comment-1656630-20110818200837

There was never a plan to prevent users from editing each others' subpages -- that must have been a misunderstanding somewhere. There was, however, a plan to prevent users from editing each others' profile pages (which was how Profiles 2.0 functioned -- so it was already true for a whole bunch of wikis).

We scrapped that at the last minute, though and are allowing people to edit each others' profiles.