The stats don't show a lack of popularity for shaman, they just show a ridiculous popularity for other classes.
I am taking that out of context a bit-- Tharfor is basically saying that Shamans are in the right place, and it's other classes that need to be balanced on to them (and Thundgot later wants it clarified as "certain" other classes-- Druids and Warriors specifically). But as if the Shaman forums weren't enough of a firestorm, that statement has set off a whole other explosion of complaints. People are even asking if a statement like that is supposed to reflect Blizzard's feelings as a company or just Tharfor's as a CM.
I feel for Tharfor-- at least he wrote a lot on the subject, and at least he stepped up to talk to shamans about this, even when I'm sure the other CMs were tired of banning people after dot-shock. But this Shaman issue isn't a problem that can be talked out on the forums-- serious changes need to be made in game. From the missing Shaman review before BC all the way up to the new Stormstrike icon in 2.4, Blizzard has done very little to cure the basic problems with the shaman class (totem length and mobility, and mana management), and posting statements like the one above isn't helping.