It takes a lot of brick making to get a brick of Sodom and Gomorrah, which is fine because you'll use a lot of bricks to build the wall. The problem is where to store them all while waiting for that special brick to drop. When sign storage was removed it was said that the devs will implement mass storage for raw materials as the need comes up. Well this is me saying that the need has come up.
Btw, why is it specifically brick of Sodom and Gomorrah that's required for a wall? A brick of Jericho would make much more sense.