

The Moon has the benefit of possibly being a refuelling or assembly spot for spaceships. Due to the lack of atmosphere and low gravitational pull, it may be more feasible to launch larger and heavier spacecraft from there (an alternative is assembly while in orbit).
Also for the clout of being an interplanetary species.





It may be possible to harvest fuel on the moon itself. Also the amount of work to keep that in orbit, etc, the moon may be more promising.