I think someone brought up a good point.
Shields are supposed to enhance your defense. There are already penalties associated with using a shield. Reduced vision, slower weapons, more stamina drain. In return for those sacrifices, we get an enhanced defensive capability.
When you allow a kick (which should be unblockable) to lead to a free hit, you are not removing the defensive advantage of a shield, you are removing all defensive ability altogether. This is simply an unbalanced game mechanic.
I understand there is a problem with turtling. There are ways around turtling. Swing from different angles, hammer away until their stamina drops. Occasionally you will run into the super-player who has an impenetrable shield defense, but it certainly isn’t too difficult to hit past a shield.
This is ESPECIALLY true with MaA’s, because they have dodge and very fast, wide swings. MaA’s have the easiest time getting past a shield, and their hatchet can kill a knight in 2-3 shots. When you combine dodge, wide swings, quick swings, high damage AND THEN on top of that an unblockable kick-hit combo, it simply puts knights at a huge disadvantage to MaA’s regardless of skill.