Originally Posted by
Shadow_in_the_Mist
As I said in my earlier post, teleporting isn't entirely perfect - blind jumps can be fatal, easily. It's a great defensive tool for their WorldShips, but for offensive purposes? Not so much. They're stuck mapping the galaxy out by way of phlogiston sailing, and using teleportation to retrace their steps.
Plus, the biggest reason is that they don't want to. Why would they want to fight wars with anyone? Dead people won't give them money for stuff they make. They don't want to take territory from anybody. War is literally no purpose in their society.