At the end of Guardians of the Galaxy, the main protagonists decide to store the Orb (containing one of the Infinity Stones) at Xandar with the Nova Corps. However Xandar didn't exactly strike me as a secure location, since it barely managed to resist Ronan's attack and was only saved thanks to the intervention of the Guardians.
What was the logic behind leaving the Stone on Xandar? Is it simply a movie plot to make sure the Orb can be easily stolen in future movies?