Well, of course you wouldn’t be able to win against a hacker who plays Paladin cards in their Druid decks, and advances their Untapped Potential despite using all their Mana.
Edit: I should probably clarify what I mean, before someone understandably points out that I misunderstood and to help rather than jest. 
If you drew perfectly and lost, two things are likely:
- You did not actually draw the best possible hand you could have against that deck.
- Your opponent also drew their perfect hand. All decks have their ideal draws, which can be extremely powerful.
Quest Paladin can put down an absurd amount of value that Druid as a class simply cannot deal with. You have to survive Quest Druid’s explosive mid game and then start to whittle them down with what can easily become infinite value, and pressure them more intelligently in the first few turns.