Being out in a field during a lightning storm is not a safe place to be, even though there are MORE dangerous places to be (such as leaning against the back stop). No one is arguing that the dugout is a safe place.
Being directly hit by lightning is not the only hazard. The charge will travel along the surface of the ground for some distance, and this has nothing to do with how tall the item directly hit is.
While lightning TENDS to strike the tallest grounded object, that is no guarantee. It will TEND to strike the tallest object in the middle of a sports field.
