I never saw anything that said they were the bridging the gap between non-Council members and WoW developers. The WoW Community Council Welcome Post says: “Welcome to the WoW Community Council forum! This forum is where WoW Community Council members and Blizzard representatives can post about anything related to World of Warcraft.”
That just says that IF you got picked for the community council the devs are more likely to notice what you post (but still not guaranteed). On the up-side of your complaint, that same welcome post also says: “We will continue to add Council members as often as necessary to bolster every kind of discussion here, and Council members will be removed one year after they were first added to the program.” So every year you could reasonably expect some/all existing members will be rotated out in favor of new players.
It really IS a chosen council. Council members represent their own opinions, not those of the majority. Nor are they obligated to try and represent the entire community other than by statistical sample size. The welcome post says “WoW Community Council members have been selected from among the many thousands of applicants for their varied experience playing and posting about the game, as well as their diverse perspectives.”
I think you just misunderstood their role.