Cards in hand is just another resource, like board presence and health pools. Having a significantly greater card lead over your opponent is just another form of overextending, which can be abused both by cards like Divine Favor, along with milling-based cards like Oracle, Naturalise, and Sap-type mechanics.Would you say that Mill Rogue is terrible? Because I think the cards it uses just promote different gameplay, and I admire the way that mill decks are constructed and played, even if they are a little mindless at times.
Personally I'm not a fan of mill in the first place. You either get effortlessly stomped or your foe can't do a single thing to stop you, it was okay when it was a gimmick, but now it's not that terrible.And here's the thing, lets say the paladin has seven cards in hand, you have five, they play six cheap cards, and a divine favor, and all the sudden you were punished for having a hand of any meaningful size. How would you suggest playing around that? Are we just not allowed to ever have a hand?
I admit my example was not practical, it was just exaggerated for effect. The point is, the paladin can reasonable dump some cards to get less than you. This card is very unlikely to not get at least two cards, which means it's generally stronger than Arcane intellect, which is run in most mage decks as it stands. I personally think there should be a way to punish players for getting insanely ahead in card advantage, but those cards already exist.Goblin Sapper and clockwork giant are good examples, and I think even divine favor could be balanced, if it costed four or five mana, so that it wouldn't be a better arcane intellect for aggro.