It gets more clear when you steel-man the "make humanity better" on earth and find out that the powers-that-be will fight you if you try to objectively make lif

It gets more clear when you steel-man the "make humanity better" on earth and find out that the powers-that-be will fight you if you try to objectively make life better for the billions here because you will need to disrupt various power structures to do so. Mars is an aspirational, asymptotic ideal that could get more people in space/lunar and possibly also prove to be wildly profitable in some applications - while also being somewhat orthogonal to existing terrestrial hegemonies.