I think it matters a great deal! If that result comes at the expense of - let's say - progress fighting climate change because Elon also ended up defunding and destabilizing a lot of science with the same instincts that got him to proclaim his mission of going to Mars, it is not obvious that we only ought to focus on the end result, and even if we do, that only one set of end results need focus.

We may be closer to going to Mars, an extremely inhospitable place, at far greater expense than simply making the world we were evolved to survive in a little better.

The way things are going here on Earth (thanks in part to Musk and "Glorious Leader" Trump), we ain't makin' it to Mars before global resource wars completely cripple all our scientific aspirations, including becoming a "space-faring" species. It's all wasted effort at this point, because nobody seems willing to do what it's gonna take to ensure that humanity has any future at all.