User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-5774152-20130216040402/@comment-3146930-20130216054527

Well you have to consider that Gaea's forces are mostly monsters and would reform in Tartarus almost instantly. Because of this, if the forces on the Tartarus side were defeated, someone/something in Tartarus would have a very short time to close the Doors of Death before being faced with a swarm of monsters all ready to attack again.