Trump actually did use the DPA to order GM to produce medical ventilators. Because a car company will have no problem retooling all of their factories to pump out medical devices. I believe that just taught all the CEOs of companies like GM that they shouldn't offer to do a damn thing publicly before they've already got a program in place.

This is as opposed to ordering one of the several companies in the US who already make medical ventilators to simply make more ventilators.