I absolutely agree that doing nothing can make depression worse, but unfortunately when mental illness is severe, working is often not an option.
I've been on disability for about 7 years now. I am currently working part-time but could not have done that when I first went on it. Everyone is different. I'm sure you meant for this post to be helpful but it might end up hurting those who want desperately to work but just cannot do it at the moment.
Also, there are many other things one can do to stay busy if they are not able to work...such as volunteering, exercise, hanging out with friends, meditation, etc.