 Why were the beings readily applying for the trip to Earth?
The aliens came in every shape and form, in all colors and textures—and all of them eager for a Corrigan contract. It was the isolationism of the late 29th century that turned me into the successful proprietor of Corrigan's Institute, after some years as an impoverished carnival man in the Betelgeuse system. Back in 2903, the World Congress declared Terra off-bounds for non-terrestrial beings, as an offshoot of the Terra for Terrans movement. Before then, anyone could visit Earth. After the gate clanged down, a non-terrestrial could only get onto Sol III as a specimen in a scientific collection—in short, as an exhibit in a zoo.
 If was their only opportunity after the Terra for Terrans movement.
 They were looking for a way to overturn Earth.  If was their only opportunity after the Terra for Terrans movement.  They were bored of their lives on their home planets.  They were hoping for handouts.