That's just it: you cannot blackmail all the gods. Even being close to gaining control of where the rift opens is enough to have the gods voting to destroy the world. The gods can unmake the world faster than the gate ritual can be performed. TDO would know this if he had maintained contact with the other gods.
All of the deities have a vested interest in not allowing anyone to manipulate the rifts. Because of their rules they mostly choose to not interfere other than through their clergy. So, trying to use the rift is little more than a complicated way to commit suicide, and that is all it ever was.
Kubota might think he can use the bluff of controlling the gate, but he was not suicidal.