This is my thoughts. Since we run closed systems, the bacteria and Biome are always in competition with other strains/versions. Only the strong survive. The Bacteria in a tank that is one year old is different than a tank three years old. So if you get your rock from a existing system or LFS, you will only have the Biome that is existing in that system at that time. The ocean isn’t a closed system. Biome is more expansive because it can find it's own niche. One needs to "feed" their Biome by introduction. This can be from NSW, ocean sand or rock, even coral from other systems. You then also have to feed the system with Phyto, pods and rotifers. You need to feed the things that feed corals.
