"These ruins are near a location confirmed to have a bridge to the elemental planes in the future. The connection is there. Consider this while you begin excavating and exploring these ruins today. And be aware that there may still be monsters around the area. They may be attracted to us and not deterred."
Since Onyx had chosen to remain with the ruin investigations and the serpents who had the class to hunt them, he had been very busy.
Specifically, it wasn't the fact that the ruins held a lot of potential. Instead, it was the fact that the ruins held a lot of information being used within Genesis right now. Getting information about ancient monsters was proving to be much more valuable than the resources that might be found intact.
Simply because these ancient monsters might have survived. Or they were ancestors to the monsters of today which were changing due to the increased mana flow of the world. Knowing was a small portion of the battle.