I'd agree space programs are hugely important and they do have great spin-off benefits that we can't foresee.

Even the colonisation idea is great to focus innovation on a specific goal .

But the whole argument to colonise for the benefit of mankind is morally suspect: mankinds future is on earth . Yes there are huge problems here but they are relatively easier to solve with much greater return on investment.
I find that these tech moguls in some aspects are lazy thinkers . They like to come up with flashy tech and then find or invent problems to solve it with.
When it comes to real world complex problems , they tend not to have the patience or courage to deal with those.
One concrete example , desertification ; wtf are we trying to solve water problems on Mars if the payoff for creating massive water solutions in say the Sahara would benefit literally billions of people.
The whole spiel of mankind needs to colonise other planets is a bit bogus given a choice between the 2 : technologically getting water to the Sahara is several orders of magnitude easier to solve and will do much more to safeguard humankind's future then the time and effort spent to maintain a few dozen people on Mars .
Asteroid exploration / exploitation might make a lot more sense with spinoff benefit of maybe some protection against catastrophic impacts.