Actually, they simply refused to believe that Lu Shu could follow Li Yixiao to overseas remains.
Their perception on overseas remains was about the same as that of individual Practitioners, that they were equivalent to an upper-class party, accessible only by the elites. In other words, people would fall in love there and might even climb up the social ladder rapidly with the good items obtained inside.
In addition, they could also expand their network…
It was an overly simplistic and optimistic view because their network might stab them in the back too. For instance, bloodshed between Practitioners was not rare in the Koh Chang remains, and individual Practitioners were mercilessly enslaved by big organizations to serve as canaries in the mine. It taught everyone a lesson, that the cultivation world followed the rules of the jungle.