Echo
Much like with the Incomplete Heavenly Path, a Sect had to send in disciples to gather a certain amount of Fate and Faith for the Sect in question to be able to transcend to the next level. Ryu had been able to do it and reach an adequate standard on the Incomplete Heavenly Path, but the Complete Heavenly Path was a completely different animal. Without several disciples performing excellently, it would be simply impossible to reach this appropriate standard.
The last power that had managed to reach this standard was the former Frost Clan, but it had already been countless generations since then, and before they could even readily accept the rewards that came with their success, they were eradicated almost down to their last man.