I'm not sure whether you're making a comment about prison society or society in general. Penal labour sounds like a pretty bad idea to me. But I can see a few reasons that chess might be good for rehabilitation (some referred to in article):
* Simple, indisputable demonstration of intelligence. People from deprived background often have low self-esteem and very little evidence to show for their smarts, even if they are in fact intelligent.
* It's traditionally a slow, thoughtful game, in stark contrast to the stress and demands of the outside world.
* It provides escapism by totally focusing your mental faculties onto the world of the board.
* There are few external expectations. No one will be upset if you make a silly move, like they would if you make some bad stitches.
Prison forced labour might not be a good idea. Prison labour as an optional thing is definitely a good idea, and most prisons give prisoners the option to contribute, at least to the running of the prison, in exchange for certain privileges. The jobs include working in the laundry room or serving food. These are not intensely engaging occupations, but they are an improvement over the monotony of prison life, and give people the opportunity to excercise certain skills useful in the real world like teamwork, diligence, etc.
* Simple, indisputable demonstration of intelligence. People from deprived background often have low self-esteem and very little evidence to show for their smarts, even if they are in fact intelligent.
* It's traditionally a slow, thoughtful game, in stark contrast to the stress and demands of the outside world.
* It provides escapism by totally focusing your mental faculties onto the world of the board.
* There are few external expectations. No one will be upset if you make a silly move, like they would if you make some bad stitches.