I wouldn't have reverted had the link appeared on any page dealing with the user in the context of a user, but the watchlist editor is explicitly referring to the page, not the user. Ergo, it seems completely inappropriate to me to arbitrarily change the semantics of the context in which the title is being displayed for a single namespace.
There is no need for the watchlist to just be a list of pages. It could include anything watchable, including users.