Yes. Immunity on one side of the building does not suddenly make you more tactical.
You can lock down an entire building from one side because the enemy has to enter your arc to shoot at you and get destroyed. That is not good for gameplay.
But the immunity would go both ways and still allow the attacking player to flank. It just makes no sense that he should be able to shoot through a wall while I can't. How can you say that is good for gameplay?