One reason we should colonize mars is because we need to make sure that are species the human race lives for as long as possible for all we know mars could be are last chance of survival if earth gets destroyed by lest say all the volcanos erupted and it destroy earth we would have to leave and go some where else but we wouldn't be able to because we would have no where to go.
Another reason why we should colonize mars is the fact that what if we find some version of life on mars we would be able to help them survive or they could help us we could tech them how to speak and for the