Seriously dudes, learn to hearthstone? I don't get the complaints, I keep getting these play 50 class card quests and I love it. They are sixty gold, just do like Gav says and make a deck full of class cards and hit casual. You're done in no time. Much easier than winning five games, which is often with classes you didn't even want to play.
Its also been hilarious loading up a wild rogue deck with nothing but 0 to 2 cost class cards and actually rushing people down and beating them. Or loading a warlock up with every murloc in the game and actually stealing a couple games. Easy fucking 100 gold that quest.
The most annoying thing is people in casual not realizing you are just trying to do your quest. I deliberately let them win, make it very obvious and they still concede on me.
And shit like slippery's complaints that I keep seeing, how do you not realize at this point that those battlecries or deathrattles don't count as "playing" a secret? Or that playing a druid isn't literally playing a beast, etc etc. Hell, for secrets you can play secret hunter and get it done pretty easily and its actually a fairly competitive standard deck.
If they hadn't added the deck slots maybe I'd get the annoyance more, but I find it easy to have a rotating quest slot to make these decks for doing dailies.