Cooperation instead of "forcing" or punishing would of course be the desirable one. But in reality and in especially EFL settings, where students have no other and outer environment to practice L2, class time is the only chance they can use for practicing it. And convenience, as ultimate freedom, sometimes turn the course into vicious, lazy and 'fun' cycle of L1 communication. And mistakes, as long as they are the results of some effort to use L2, they are admirable..