Program with Ruby long enough and it really starts to feel like a religious experience. You feel like you can literally do anything. Things you can't do with it just don't seem important anymore.
Rails just takes Ruby and puts it on steroids.
Bad joke aside, and I may be a naïve newbie, but what is stopping someone from writing tons of implicit code during their most productive work hours and when they're tired go back and make comments that make the code more explicit. Seems that this would get the best of both worlds in that you'd be able to be hyper productive when you've got the mental resources and then taking that extra time to make sure whoever stumbles upon your code later doesn't have to deal with a huge learning curve.