McKitric's idea...
Wouldn't that pretty much mean the missiles would not launch? WOPR would play through all the scenarios, like it did, and not launch since "the only winning move is not to play" even when it thought the missiles were inbound? At least with the men in the bunkers, 80% of the missiles would launch. Isn't 80% better than none?
(The ones who refused to turn the keys still should have been demoted and given janitorial or some jobs not related to actually defending the country.)