I love the idea of humanity expanding out into the cosmos, it feels like space exploration is "the Future." But I can't see how SpaceX's Mars colonization plan

I love the idea of humanity expanding out into the cosmos, it feels like space exploration is "the Future." But I can't see how SpaceX's Mars colonization plan makes economic sense in the current day. No matter what technical advances they come up with in getting people to Mars, it doesn't change the fact that it is an inhospitable planet. What unique resources are on Mars that makes it more profitable than say, colonizing the Sahara desert?