Not unintelligent. Plain.
Eisenhower required his subordinates to submit their proposals to him on one foolscap page. His detractors said that that was because he was dumb. He said that if what you’re proposing is longer than that, you’re obfuscating to cover your ass.
Eisenhower may have been the greatest planner and coordinator of men and materiel in US history, perhaps with the exception of his boss, George C. Marshall. He knew that somewhere, someone had to say, “I think we should invade mainland Europe by an amphibious landing in France,” before all the work got done. Only a proposal that unequivocal, carefully reasoned beforehand but distilled to its essence, is worth consideration.
It’s all equivocation now. In between the lying, that is.