The death of a Grand Duke Clan potential heir was too much. Mason might have been ranked second amongst his Clan's Quasi Golds, but that position alone was more than worthy to become a future pillar of the family.
No Clan was built off the back of one genius. Even if they felt right now that he was inferior to another, it wasn't by an exaggerated amount, and it certainly wasn't enough for them to feel that he was worthless.
This was only more so since Mason was a key figure in their position in the Obsidian Eclipse Sect as well.
As per usual, Clans always kept their best geniuses in-house, only sending out those beneath them to join other organizations like the Sects and the Imperial Academies. This was how they could prevent their geniuses from being influenced by ideologies they didn't agree with, and also keep them from being unnecessarily targeted.
