That we are still here on the planet Earth is evidence that no extraterrestrial intelligent life, if it exists, has achieved intestellar travel. Our beginning steps toward interstellar probes suggests we will be the first to arrive at this stage. Thus humans will be the first in and the last out.
Thats a theory.
Here is another one....our planet has ALREADY been wiped out and our resources taken. What we see today is merely whats left over.
That's a stretch...no pun intended.
And we’re going to bring our Moon with us...just because we can! (obscure SciFi thing).