Quite possibly for the same reason that we aren't spread out all over the galaxy ourselves. The speed of light limit, and the enormous energies or time needed to traverse the galaxy put an enormous barrier to its exploration. Those barriers may be untranscendable, making them as difficult for others as they are for us. 42 posted by yendu bwam In our current physical definitions ('laws' of physics?), the speed of light appears to be a barrier and the temporal gel of present time appears to require trabersing moments as if topping grains of present time along a temporal line. It is not outlandish to believe there is a better perspective available if we can discover the key to unravelling the foundational principle. Should someone discover a way to unify all the known forces, the key to transcending temporal limits as we now believe them to exist may be a natural outcome.
Those who actually work in that field disagree about your hope of transcending the speed of light. But perhaps you will prove them wrong. I hope so. The inter-stellar empire I hope to found will be slow going otherwise.
Also consider the miracles of Christ, such as walking on water, making the fishes and loaves. These issues never get very well addressed in many studies other than their mystery. I believe there is a balance to consider these events wihout becoming gnostic which is better understood by studies of the Holy Spirit and discerning the meaning of faith and belief.