It wasn't so much an effort to limit military buildings as it was an effort to balance the immense power difference between cities and spacecraft, that heavily favored cities. Spacecraft were hopeless against cities when it should be the other way around.
When you rule the air, you rule the ground. When you rule space, you rule the air. This fits with Star Trek lore, where in several episodes they said the Enterprise was capable of leveling every structure on a world or reducing the entire world to cinders.
With this change, the war capabilities of the most built up world are roughly equivalent to the war capabilities of the largest possible space station.
To achieve that balance by limiting the number of buildings, that limit becomes 1, maybe 2.
When you rule the air, you rule the ground. When you rule space, you rule the air. This fits with Star Trek lore, where in several episodes they said the Enterprise was capable of leveling every structure on a world or reducing the entire world to cinders.
With this change, the war capabilities of the most built up world are roughly equivalent to the war capabilities of the largest possible space station.
To achieve that balance by limiting the number of buildings, that limit becomes 1, maybe 2.