The overall reason is documenting not only the database, but the size and scope of the database (and basically the project it supports). This is probably not that overly important to others, but when looking at a database, it give a sense of the scope of the whole thing. Seeing the number of stored procedures give you a good idea right up front of how an application is addressing the database. Seeing of line count of those stored procedures shows up front how complex they are (or not).
Really just like the front page, being the introduction of the database, with maybe the statics being on this front page. There is another product called SqlSpec that does a nice job on the front page. It's a slow tool, and doesn't let you edit like yours, so right now I'm kinda of using both.