Rest is of course very important and should be recognised by the medical establishments BUT some people are so ill that just living brings them out of a resting state.
I'm "only" moderately ill, but I have a child, and just tending to her brings me out of any resting state I might achieve. It's not possible for me to rest with little me shouting mummy mummy mummy all day long - oh joy at the thought of the summer holidays!
True resting really isn't an option for most people.