We deserve to because we can. To continue life beyond what the planet us capable of sustaining is a kind of ultimate purpose to life. Building structure to live in instead of planets.
If you can rape someone, do you deserve to because you can?
How is "continu[ing] life beyond what the planet is capable of sustaining[,] kind of ultimate purpose to life"?
It's more about leaving the limitations of the earth, and ensuring the continued existence of life. In a way life was created to allow DNA to propagate.
