the rule is designed to limit you lining someone up from behind. that's it.

think of a play in the corner where people are fighting for the puck and a guy is facing the boards for a few seconds and someone comes in and labels him from behind.

that's a penalty.

last second adjustments that put the puck carrier in danger are NOT the hitter's responsibility nor should they be the focus of the rule.

the game is changing in a bad way.