I think like many other council committees, a lack volunteers/interests have led various council committees to dissolve, be absorbed into another, or stagnate. I think a lack a volunteers willing to serve on council committees from both inside and outside of Scouting has contributed to this.
In my council's case, a core a group of "council favorites" head-up the majority of the remaining council committees, events, and projects. I believe my council likes to keep its avid supporters close and insulate themselves in the process. I can't say the same for other councils, but I do know the councils I've been a part of have often overworked,burnt-out, or flat-out burn bridges with many of their volunteers.
Just my two-cents.