There's no way you could have grasped all of that so quickly, so let's go back and oversimplify. Aliens come from other dimensions; while here they cannot disappear--but they can be invisible to us. They cloak, and such. The middle-earth lizards live here--they don't leave, they just go "underground". But while up on the outside, they have complete control to appear, disappear, change, and transport anywhere else on the planet.
So the question is: would you rather be able to be invisible to humans, and do space travel? Or would you rather be stuck on earth, but with the ability to actually disappear and reappear somewhere else?
Aliens can make it look like they disappeared, but they're really just invisible to humans. Lizards can actually disappear at any moment, and stay gone forever.
This exercise is for you to see where your central perspective is; would you rather have control of what you know, or would you rather have the perspective of an inter-dimensional being? Did you come to your answer easily? Why or why not? I did NOT come to my answer easily; I have many questions. But if we are just going to take what we know now as humans, then I would stay here with the lizards...wait a sec:
I would stay here with the lizards, and fu@k with people for a year or so, waiting for the aliens to come back and blow this labratory up. Why? Humans are weak; we can't survive out there in unknown atmospheres. This planet is all we have ever known, so I will not trade a 'lead role in a cage' for the 'walk-on part in the war'; thank you. So; who wins? The aliens win--they can go to any other dimension. If the earth blows up, then all the lizards die; awww. But while we are here, the lizards rule...Later, if I do this exercise again, in another dimension, I'll probably side with the aliens. If this makes any sense to you, then you have issues.