Check the discussion here: http://lotrtcgwiki.com/forums/index.php/board,40.0.html
Long story short: Decipher set up the Players' Committee for SWCCG because they wanted to maintain a fanbase that would transition to LotRTCG. They didn't care when LotR died, so they didn't set it up. The players tried to organize one, but ran into legal questions and didn't want to hire a lawyer to figure it out.
Short of that, people just create whatever projects they want (Second Edition was bandied about for a while, but then I think people realized how challenging overhauling the whole game really is.)
This (although the link you gave is not to a specific thread).
The player base for LOTR TCG is pretty fractured when it comes to what we think should or should not be changed or added to the game. Since Decipher didn't set up any kind of committee, there isn't any person (or people) that speaks with sufficient authority that the player base is just going to accept what they say.
The consensus for now (and the foreseeable future) is to simply rely strictly on official rules, rulings, and clarifications that came down from Decipher. No new cards, formats, or rules.
To top that off, for many of us, playing LOTR TCG on a daily basis means playing it online via Gemp. Gemp is a website that was created and is maintained by
one guy, MarcinS. He has absolute control over what rules, formats, and cards people can use there, and for the most part, he is a strict adherent to the "nothing new" policy. In addition, he really doesn't make changes to Gemp very often anymore, so even if he were to consider allowing new stuff into the game, the chances that you could actually get him to sit down and code that in are very slim.
So a committee can invent all the new stuff they want, but (1) most of the player base isn't going to listen to them, and (2) even if the player base were in favor of it, new stuff almost certainly isn't going to end up on Gemp, and so committee decisions would have zero effect on the way many of us play the game.