If the body is moving away from the ball, the motion takes away the force of the ball. Dignity when dodging a ball can be a luxury. If the body is falling to avoid a ball and trying to maintain balance at the same time, it means two sets of muscles are working against each other. It is better to use all the muscles to flop, fall, dodge, or whatever, than to get hit. Remember, a body falling away from an oncoming object receives less of a blow.
Some pitchers believe that they pitch better after getting stung.
It tends to remind them to concentrate a little harder and brings them back into the game. The satisfaction of being able to consistently pitch to an elusive point in space, where the ball and bat meet, is definitely well worth the time and effort.