For LotR, I don't think there was any particular group that received Decipher's support to inherit the mantle. I stopped collecting after the culture reboot and didn't keep track of things too closely, but there was an online card store that had an active community on its forums until after the last set was released. When that site closed, someone was kind enough to create a new forum (TLHH) to keep that community together.
Some attempts were made there to continue the game in some more organized capacity, but maybe a similar scenario played out in other forums as well. There was the desire and need to keep enough people invested in the project, but I think issues such as the lack of authority, inevitable disagreements (something as "simple" as fixing the game as it stood could generate enough heat to warm the toes on a winter evening), and real life getting in the way of the rudimentary organization in place all led to eventual disinterest, and possibly eventual disillusionment at the entire idea. People just went back to the rules and house rules they liked. And when people stop participating, it's really easy to kill a project.
A LotR Second Edition on a site specifically meant for that might just be the clean break that's needed, and I hope it takes off. As for the Continuing Committee, all I can say is don't take these folks for granted.