Let's say you are playing DOTA and are ambushed. You fight bravely but the enemy outplays you and you die.
Now he gets a level, and buys some nice items. You don't even try to fight him but he pursues and kills you. Again.
Later he is several levels ahead of you, full of gold and most towers are gone. Your team is cornered in your base after a long, drawn out fight, clashing the relenteless waves of enemies and critters and yet, you deep inside, you know you already lost.
That feeling of despair and hopeleness, that's what I think drives DOTA players. To utterly crush your enemies. From destroying their ancients to denying their kills. Isn't about winning as much as it is to make the enemy lose everything.
Including their cupcakes.