As much as I agree Stewart is a hosebag, lack of military service does not indicate an unqualified opinion. Cruz, Palin, Ben Carson, Rush and others all have solid conservative creds but did not serve and some (not all) would make great leaders.
Governor Palin was the leader of the only state with active duty forces, due to its geographic location. No, one doesn’t have to be Ike, Grant or Jackson to lead the country.