Le Mob has a strong social element with evening events and a chance to meet like minded enthusiasts. The in-circuit parking which is available to organised tours is also an attraction. Depending on the grade, Le Mob also includes low level helicopter flights around the circuit during the races. I agree that it is not difficult to organise your own trip but sometimes it is just nice to kick back and let an experienced organisation take care of the details so that all you have to focus on is enjoying the occasion.
To each his own.
Don.