Because, why not? I really would like a mode where you have only a specific amount of time (in space years or whatever it is called). Because you now have only finite time you have to think of new tactics to create a federation faster, giving the game the game a dynamic twist. For an exampleI really take my time to grind my resources and connections high before I go on to reach the goal. You will have less time to do it and have to make decisions what you would do next instead of doing eveything in a chain.
Maybe there should also be an option that allows you to select how much time you want to have as limit.
What do you think about it?