It seems the whole shaman class is having issues with this sort of thing Normally its 1 shaman with the whole who cares what spec he is we need bloodlust.
I have been and seen several guilds that just dont bother taking more then 1 shaman of any spec to a raid cause well whatever a shaman can do someone else can either do better or just as well but with raid utility.
A perfect example of this includes:
Enhancement: DKs have virtually the same amount of buffs they do execpt on aoe fights do about 4k more dps... Which include a lot of fights in the whole of wotlk nevermind ICC. Give this with some of the worst gear depenency issues in any class and its a recipe for disaster.
Elemental: Nice dps if you know the rotation but unfortunately because of stupid little issues which shouldnt matter they lose lots of dps.
On many occasions I have heard shamans complaining about having Moonkins in the group because it stops there buff from working which means 10% extra damage for them.
Also yes they have WoA and other nice goodies but in the perfect 10 man group or even in a decent 25 man group they are overlooked for pure dps which can pump out largely more dps.
Resto: Lets get something straight first resto shamans dont suck, what sucks is there lack of actual useful raid utility (Unless there that 1 shaman for BL) also whatever a shaman can do someone can do better, they have no area they excel in.
Its the same reason warriors dont take agility as a main stat for instance its useful that it gives a little crit... but its actual use is so little that taking Strength is just more useful being in the middle and a jack of all trades master of none really does put them in a terrible position After all ask yourself something which would you trust more to do his job in a ideal world where every player was equal? I know it would be a resto druid for aoe anyday and a holy priest or a Holy pala or a disc priest for single target.
But hey what do I know only been playing shamans since release.