In chess, defensive play can be very effective as long as latent power is developed waiting for the moment to be unleashed.
I agree that defensive play beats an aggressive style in the volcano variations, but not in the open variations. I pull back to regroup on occassion, but typically press the attack from the beginning of the game until the end. I don't play the volcano variations any more because it doesn't suit my style even though I have done relatively well playing those variations as well. Currently, I only play Open Rush and Corner but not here. I have one 3rd round game of Mini going in a tournament I joined by mistake. I expect to lose it fairly soon and be done with that variation for good.