To paraphrase the guy from the thread on Visa predicting divorce [1]: Slightly off-topic: if you post something with a misleading title that you can improve, please do so. This article has no real information on how citable public documents will change your life, just the assertion that they will and that you should help.
IMO, it goes off the deep end after the WHY section. The scientific community has been dealing with the issue of citability for a couple of decades now (that I have witnessed) but, it seems like the folks at citability.org are intent on reinventing the wheel on this one.
That's a false analogy. The legal community deals with well-documented, stable, and easily cited statutes. There are strong incentives driving clear presentation of current law. The objectives outlined in the OP would not be served by those incentives, because they are concerned with all government documents, whether they have made their way into law yet or not. Such documents can be unstable and hard to find, so providing clearinghouse through which they can be cited in a time-aware fashion would be incredibly useful for tracking the evolution of proposed laws.
I was talking about citations on the web but agree with your point. Quick access to cited material means more time devoted to solving the client's problem (or serving more clients - both are good outcomes).
[1]: http://news.ycombinator.com/item?id=1249539