Zhouyang didn't want too many people to know about the discovery of the Spirit Stone mine in the short term.
Although the Zhou Family already possessed the power to fear no one in the Boundless Desert Sea Cultivation Realm, the interests involved with a medium-sized Spirit Stone mine were too significant, making it necessary for him to act cautiously.
Moreover, for the time being, the Spirit Stones stored in the Zhou Family's treasure vault were sufficient. Extracting more would only result in a pile-up in the warehouse, unable to be converted into urgently needed treasures.
Additionally, all of the Zhou Family's current projects required manpower, making it difficult to spare many people to travel afar to mine the Spirit Stone ore.