I think this just highlights how difficult it is to balance games. Alot of players (with zero experience in game design) think it is trivial, but it isn't... not by a long shot. So, practically speaking, it's impossible. Especially given that you can't please everyone in any game, and in this one, when you change one card, you affect 3 modes (standard, wild, and arena).
I agree that the first post-DoD release nerfs to shaman were necessary. Shaman was put more in-line with other decks and classes. Galakrond shaman then started using the frog package, and while the dragon's pack nerf definitely hurt, I think Invocation of Frost was the real kicker. It threw a wrench into the flow of spells for the frog package, along with a eliminating a good turn 1 play with the card.
Then you have the known fact that shaman (like priest) has one of the weaker basic / classic set of cards of all classes. So once you hit current rotation good cards for shaman (or priest) with a nerf, they can't "fall back" on their basic / classic set like other classes (*cough* rogue *cough*).
On top of all this, card games are far less granular for adjustment than say an RTS or FPS. In those games, having fractions of numbers is fine, or having large numbers to give greater granularity (for the minimum change of 1 integer) works too, but using such large number / factions / decimal points is far less practical or enjoyable to play in a digital card game. I mean, just consider Fiery War Axe: it went from one of the best weapons in the game at 2 mana, and in pretty much every warrior deck regardless of archetype, to being not a card in any relevant meta deck for years at 3 mana. And that was one of the smallest changes they could make to the card...
There is no such thing as a "balanced" meta in my opinion. Only metas that have some imbalance versus those with alot of imbalance.