Feng Jun wasn't certain whether Yongyi Duke's question was a form of probing, but he clearly expressed that these metals had nothing to do with cultivators unless they were willing to accept them as ornaments made of mortal materials.
To be honest, even on Earth, most of the platinum group metals exist as luxury products—because they are beautiful enough.
Metals like rhenium, which are extremely useful, are ultimately the minority, though there are a few types that can be used as industrial catalysts.
Feng Jun didn't worry about them taking those metals to use elsewhere, but merely mentioned that the luster of platinum group metals is mostly quite appealing, which could lead to considerable loss if collected as luxury items.
Therefore, he must emphasize that other cultivators would find these things useless. As for those who might not believe him, it doesn't matter; after all, cultivators would never be interested in things without spiritual energy.
