I've done this with several orgs now, and even with backing from the VP level, at best I get belligerent participants, and truly I cannot tell if their resistance is that they don't like the decisions we make, or if they just don't understand the process and want the ability to complain to someone directly.

The belligerence is that there’s very little benefit career-wise to being a good committee member on low-visibility committees. At best you get some nominal recognition, and at worst it’s a distraction from the things that actually do further your career. Nobody gets a gold star for that kind of work, but you do get big promotions when you can own chunks of work yourself (even when done poorly).