Resto shamans do not "outclass druids by far", in fact I would say Resto druids are superior to shamans by a fair amount.
There are so many reasons why LSD is superior to LSD2, but I will leave you with this, both are attrition comps, and resto shamans are a liability in attrition comps as they can be trained to the ground - not that resto druids bypass this by any means, but are far more suited to handling it -, on the other side of the coin, Ele shamans are infinitely more tanky than a moonkin especially. LSD2 has too many liabilities for an attrition comp in comparison to LSD where all three targets are effectively unkillable by a vast majority of comps.
Also, having a decent chunk of your teams primary CC attached to your healer is very powerful as opposed to having it on a DPS that is going to be the target of choice, especially a short range CC like Cyclone.
On top of that, you're ignoring the fact that Eles sustained damage is just like everyone elses with Unleash+LBolt hitting super hard, Lava Burst procs just seal the deal, RNG isnt going to fuck you over for 20 mins straight, the stars will align. Purge being such a powerful tool whereas moonkins don't get access to it, and Rshams not always having the time to do it - They can symbi it from a shaman however its almost mandatory for Moonkins to symbi a warlock. Symbiosis synergy is also vastly superior when talking about LSD, giving it ridiculous lockdown options or additional healing.