They do not have to. Every time they discipline, discharge or lay off a bunch of workers the employers are using direct action. A depression is nothing but a lockout against labor. The owners of the industries simply close up shop and cease operations because they can no longer get their customary profits. And all the laws and politicians in the world, or all the armies in the world, could not force them to start up again unless it would pay them to do so.
Business is business.
The employing class knows full well what industrial power means. They use it all the time in the form of merciless lockouts, strikes and sabotage against labor. But, they are decidedly unwilling to have labor retaliate in kind. Their machinery will produce neither profits nor anything else until it is oiled with the sweat of human labor. Against this mighty industrial force they have neither cunning nor power to defend themselves.