I can agree with this to some extent, but then the Control deck usually needs some sort of insurance policy to keep from losing the game to cards like Soul of The Forest. The only successful Control deck in the RoS meta was Control Warrior, and I think a lot of that had to do with Warpath; one of the only ways for a Control deck to counter cards like Soul of the Forest, and other sticky Deathrattle cards.
The only other strategy that seems to work is playing a Taunt minion too big for a token deck to kill. But that comes with a lot of risks of its own; against a deck like Tempo Rogue with lots of easy removal, the Taunt minion is often a waste of a card slot. Or the Token deck might run Silence. Or they might just buff up their board enough to kill the Taunt minion without losing their own minions. Then you’re back where you started.
I like it less because of its matchups, and more because it’s the type of build-around card that I like to see. Instead of crossing your fingers and hoping that you’ll draw one specific card right when you need it (looking at you, Hero cards), you start with the card in your hand, pass on turn 1, and then you earn your payoff by playing Taunt minions.
I just think Quests are a better design than Hero cards, in general.
Yeah, I kinda wish that Sideshow Spelleater was added to the Classic set. In my opinion, it would make a good tech card against a lot of decks that upgrade their hero power. Although an odd-costed version might indeed be better.