Voting "keep it". As mentioned, when a new user posts on it the thread appears in the "New Posts" area, and that's usually where I notice there's a new player. When someone makes a userpage, there's no notice, for me at least. And Kim's right, not all new players know how to make one.
Plus the age alert, knowing how they got here, all that good stuff ^_^ It's kinda like a briefing before reading the full file (the user page). Plus, they can link to their user page from there.