I actually think any request for nerfing the Quests has at least some merit to it.
Not because they are OP or broken i don't actually think thats the case, not even with The Caverns Below but because of how strangely specific they are in the way they work and how that results in a direct limitation of design space for any future expansion as long as these cards are legal in standard.
Seeing how Blizzard has been nerfing or rotating out quite a few cards because they feel like those limited design space it is still rather mind boggling to me how these Quests made it into the game. They basically can not make really good neutral taunt minions for the next 2 years because of the risk of Taunt Warrior running wild.
They can't create any more bounce effects because that would make Quest Rogue even more reliable and so on. Quite a few of these Quests have the potential to be broken at some point during their stay in standard given enough support from future expansions and thats just bad design on Blizzards part.