“Ventures like this cause solutions to hundreds of problems, and tech gets better.”
Hey, so do world wars. Is that a reason, in and of itself, to start one?
If you have to argue for your proposal based purely on possible accidental, ancillary benefits, then you might want to rethink your proposal.
Sending 6 people through space is a whole lot different then starting a World War. Maybe you need to rethink your analogy. Do you know what you have, right now, that is a direct result of space exploration sitting within 10 feet of you?
Every dollar spent on space exploration is priceless.
Simply put, the development of Human outposts and colonies on Mars is a small part of a larger strategy for spacefaring Humans which is mandatory for the survival of the Human race. It is only an unknown matter of time, short term or long term as chance permits, before Humans and much of the fauna and flora become extinct on the Earth due to the impact of a large asteroid or other global cataclysm/s. The most easily exploitable non-renewable mineral and energy resources of the Earth have been consumed to build the current state of technologies capable of embarking on the human colonization of extraterrestrial habitats. If this present Human culture were to be destroyed in a cataclysm, there will never again be enough such resources on the Earth to rebuild another culture capable of embarking on the extraterrestrial colonization efforts required to avoid inevitable extinction. If the Human race successfully colonizes the asteroids, Kuiper Belt Objects (KBO), moons, and Mars, then the Human race has an opportunity to survive indefinitely, in many tens of billions in population, and long after Human and many other living species become extinct as the result of global cataclysms on the Earth.