Think - why has this not happened in 4.5 years?
Think - how would customers feel to be forced to some
action if they don't want to continue or have to stop it?
"Don't leave the restaurant until you have finished your meal!"
"Don't leave the fitness center before your time is over!"
Would this be
an invitation to come back again?
Think - how might this be enforced? If a player shuts down his PC during a MP game, what should happen? Should the others have to wait until he restarts the game, after a day, a month or never?
Think - what other consequences are imaginable without losing this client?
BTW, no real golfer is obliged to continue if he's hurt or is in a time dilemma or if it's simply not his day. There, quitting a game may only lead to a rise in HCP, and this has been excluded here in Autumn 2010 (iirc), when the average and tier system was changed.