Another unmentioned aspect of this is Blizzard's involvement. If this build is truly unstoppable in most cases, then Blizzard's balance team will simply nerf s

Another unmentioned aspect of this is Blizzard's involvement. If this build is truly unstoppable in most cases, then Blizzard's balance team will simply nerf some aspect of Zerg to make it harder to abuse. For example, when the balance team determined that Reapers were too strong in early game, they made the tech required for them take longer to get.