Musk is actually a brilliant marketer. He built his companies around a "vision", used it to attract high quality talent and push that talent to give their best.

For Tesla it was "electrify transport to end dependence on fossil fuels and save the planet", for SpaceX it was "save humanity by becoming a multi-planetary species".

With how much he talked about it, he did probably actually believe in Mars.

But now both of these ideals have come into conflict with his newfound political affiliations, so they have to be dropped.