The biggest issue with the Mars plan is there's no money in it, no customers lined up and ready to take advantage of it. And even if a serious organization of prospective colonists started organizing and got funding now (nobody has a plausible answer for how a Mars economy would work, how it would get enough Earth cash to pay for itself) it would still take decades for them to develop viable Martian colony hardware. Even test-runs of such technology in closed environments on Earth are in their absolute infancy and have virtually no funding. As a Mars rocket, Starship is a bridge to nowhere.

Yet Starship is costing SpaceX a whole heck of a lot of money to develop. I don't think that makes any sense unless they have some other business plan in mind for it. Launching massive constellations of satellites is that plan, there's a huge amount of profit potential in the near-term if they can make Starship work. Starlink alone might make Starship worth it, but fulfilling SDI contracts could be the real money cow (incidentally, SDI is politically polarized, and this might be part of the reason why Musk has "gotten political". If Musk really wants SDI contracts then he needs republicans to fund it.)

If you're inclined to believe Musk is sincere with the Mars colonization talk, then perhaps you could conclude that the plan is to make insane amounts of money building huge LEO constellations and then use that to fund Mars colonization. But from what I understand, Musk has said that SpaceX won't be building colonies and is focused on building the ships to get there instead. Who's buying?

> The fact that NASA selected Starship as its human landing vehicle for the US's return to the moon strikes me as a remarkable vote of confidence by a highly qualified organization with far more data than we have and a lot at stake.

Maybe. I'm very surprised SpaceX won that contract, maybe people at NASA really believe they can do it. Or maybe they decided to give SpaceX enough rope to hang themselves. Or maybe nobody really expects Artemis to get that far and the whole thing is basically a joke at the taxpayer's expense. Or maybe there are people at NASA who believe in SDI and want to make sure Starship is successfully developed. In any case, even if they can actually do the moon missions there's a huge gap between hanging out on the Moon for a few weeks and making a serious go at a long-term Martian colony.