The map is filled with objects, each with a specific value. Those with many Preserves and Hives will have their value reduced, while those without will have something else to fill that value.

Even if we assume this is true (and looking at the layouts in competitive games, it's often clear that this isn't always the case), I estimate that a Preserve isn't much more valuable than a Necropolis. So, let's say 2 Necropolises and 1 Preserve are roughly equal in value to 3 Preserves, say on levels 2, 3, and 4. Doesn't it seem that removing the Preserves would make the situation much more balanced? It's clear that the internal content of the objects isn't taken into account when calculating the total value, and this content can vary GREATLY. While we can tolerate some imbalance between different types of structures like a Fortress and a Necropolis, the issue is different with the topic at hand. The inequality is often too large.