Rashi: They are stopped from agitating the land.

Malbim: He comes to proves that it would be better for man had he not been created. The entire existence of man is bad for him. If we consider all his matters and weigh his success, Simchah and pleasure, against the evils destined to come upon him, there are more evils. Some evils are due to his body, and some come from other people. Of the former, some are due to his Nefesh - emotions, natures, Midos and desires. Resha'im are agitated via envy and lust for excesses - non-existence is better than existence! And other evils come via seeking essential needs - he must toil constantly for them!