They did not want to destroy their relationship with a golden goose like Rui and had far too much goodwill for him from a brilliant relationship prior. And while they were certainly pissed about his deceit, he had never acted maliciously against them and had merely sought to do what was necessary to fix everything and pursue his Martial Path as a Martial Artist.
That was something that, as Martial Artists, they could respect and even begrudgingly admire.
Additionally, there were extreme consequences to destroying their relationship with him. He was no longer the lone Martial Artist without backing. He was a prince of the Royal Family and had developed his own faction that was extremely powerful.
Pushing him away was pushing him to their enemies.
It also meant pushing away the many contributions that Rui would have otherwise made to the Martial Union in the future.