There has undoubtedly been less vanilla control and fatigue decks since the launch of Mean Streets of Gadgetzan and many attribute this to the dawn of the Jade Lotus mechanic. Jade Druid in particular, which continues to be an important part of the meta simply outvalues most other control decks. Because of this, we've seen noticeably fewer Control Warriors which have long been the most late game oriented archetype around. However, it's fallen off like a rock now that it can't generate the amount of value that Jade Druid can and that's all because of a single card: Jade Idol.
Jade Idol initially made waves because for the first time ever there was an anti-fatigue card. As long as the Druid player uses one cast of the spell to add three more copies of it to their deck, there's no way to make them run out of steam, something traditional control decks focus on.
Reno Jackson currently dominates the control meta with Reno Mage and Renolock and that's largely because of other built in win conditions including burst and more importantly, Kazakus who helps deal with large numbers of strong minions via Kazakus Potion.
Those who miss the good old days of Control Warrior have been voicing their displeasure with Blizzard over releasing a single card that they claim counters an entire archtype. But that really isn't the case as Game Designer Max McCall explains on the Hearthstone forums.
"The Jade Druid deck has a very appealing late-game," McCall says as he begins to explain the developer's philosophy behind creating this archetype.
"You know how in StarCraft 1 it was fun to turtle in your base forever and come out with twenty Battlecruisers and steamroll the AI? Jade Druid is like that. If you make it to the late game, you’re a big favorite against almost everyone. It is comforting to know that your late game will take care of itself while you focus on gaining advantage in the immediate term, and it is fun to demolish your opponent with a ton of giant Golems. That’s why we made Jade Idol."
McCall also addresses criticism of that now infamous card.
"Most of the complaints I see about Jade Druid focus around Jade Idol. Having Jade Idol in your deck means you’ll beat grindy attrition-focused decks that don’t actively do anything other than kill all your stuff and win while you’re in fatigue. Some folks don’t like that."
More interestingly, McCall explicitly points out that those attrition focused decks don't need to be the only type of control deck out there."
"Now, it is neat that the occasional deck uses fatigue as part of its strategy; it adds texture to Hearthstone and is something to think about when you’re building decks and playing games. Jade Idol layers on even more texture: it forces those deeply attritive decks to take an aggressive stance in their Druid matchup, which isn’t something those decks usually have to do.
"That makes those games very different, which is great."
"The designers don’t have anything against control decks," McCall continues, "We don’t even have anything against the occasional fatigue deck; mill Rogue and mill Druid have been things in the past, and the only really active step we took to avoid those decks was not making a card that said ‘when you target this minion with a spell, copy that spell on every other minion in play.’ (It broke with Naturalize.)"
Fatigue isn't the healthiest of mechanics in Blizzard's eyes according to McCall, "We do prefer when games end before fatigue, and we do think control decks should have a more active endgame than merely having a bunch of removal spells, so we were okay that Jade Idol made fatigue decks worse and forced control decks to think about more proactive strategies. We are not trying to kill control decks, nor have we; people play control Warrior less, but they play other control decks more.
"I think it’s had a positive effect on the metagame."