Wherby the Intergalactic Union does not allow one species of Alien Non-Human Race to enforce the lifestyle of say A Reptilian Species on A Non-Human Bird Type; through invasion or infiltraton and deceit. Fears of one Species of Non-Human trying to compete with another Culture or World to reach First-World, Class A, Planet by sabotaging the other culture through Pseudo-Ambassadorial and Pseudo-Bi-Lateral Interaction.
But, this is just a problem that comes about because of our diverse and abundant Galaxies and Universe.All Alien Races are good.