Miyazaki and his team want to draw players into something they're terming "mortal combat" and a "rally of deadly blows". Shields encourage tentative combat in some, and that safety has been removed.
Another way in which the player is being encouraged to be more daring is the ‘Regain System’. When you receive damage from your opponents, you have a limited period of time in which to get some of that health back by landing your own attacks. The window is brief and rewards the brave. When you’re low on health, you can choose to attack, and hope to win back some health in the process, or in a more traditional fashion, choose to retreat and use a health item.