It allows crafting of cards! Actual PvP! Every three hours you get a new challenge that rewards the equivalent of crystals in MtG:PQ. If you want to whale, you spend a fraction of the cost to get exactly what you want. Servers don’t routinely screw me over, and in spite of the fact that I’ve tried to break the game–no freezes.
Pretty much all of this is in direct opposition to how MtG:PQ is run, and yet PvZ Heroes is already making a lot more money on the sales charts. Hmmm…