I would be extremely pissed off if they decided to adopt the mantle of 'voice of the fans' and started making annoucements and demands of the club and saying they were doing it in 'our name'.
And therein lies the whole problem. The more 'groups' and 'clubs' you have, the more fragmented everything becomes and it gets more and more difficult to present a 'united front' to the club.
The 'official' Supporters Club does a fantastic job but they absolutely would not regard themselves as the 'voice of the fans' for precisely the above reaons.