Having read Both of Robert Zubrin’s books, I am now firmly on the “Colonize and Terraform Mars” side. Zubrin makes the argument that, when civilizations go static, they fall. Therefore, we need a challenge. i.e., settling Mars would be that challenge. Lack of labor on Mars (like America in colonial days) will result in the creation of labor-saving devices and other inventions that can be sold on planet Earth.
Plus, I think it would be really cool a couple hundred years down the line when Mars revolts and tries to leave the Earth Alliance…
What? Why are you looking at me like that?