Call of the Wild was a highly disputed card, but it looks like the nerf impacted it more than people expected. Before the nerf, this Epic-rarity card cost 8 mana to play, and while this wasn’t hugely important for anything after turn 8 aside from maybe a Quick Shot or Hero Power, as this card got most things done that it needed to get done. Need a taunt to contest board control? No problem! Need a tanky minion that buffs all of your other minions for a potential win condition? We got you! Need to deal 5 damage to either clear the board or win the game? Easy!
This card did everything, but the issue was that, technically, casting 3 Animal Companions was still 1 more mana, meaning that the card was a sort of indirect power spike to what we’ve seen so far with Hunter. Using this card, Midrange Hunter decks reigned supreme, and a lot of the ‘counterplay’ to it became the classic “kill them by turn 8” strategy. And hey, we see a lot of that now, don’t we?
Midrange Hunter was one of the catalysts for the inherently aggro Meta we see today, and we saw a similar theme appear a year or so ago, with the dreaded Dr. Boom. In essence, this card was so strong that the counters to it were either to run a similar control or midrange style deck that includes the good doctor himself, or to kill your opponent before Dr. Boom gets any value. The same concept applies here, only due to the fact that it’s a class specific card, including it in your deck is much more difficult unless it becomes virtually a mirror match, with a few variants on tech choices.
In the end, Hunter was incredibly strong before the nerfs hit, and now it practically has its own tier below all the others. It’s not that these things are weak, but the Mean Streets not only introduced stronger archetypes, but also some cards that countered it all to well, even if the class matchup itself wasn’t hugely unfavorable. For example, playing against Midrange Hunter as a Priest means that you just save Dragonfire Potion for the inevitable Call of the Wild, and use that momentum to establish board control and win with it.