Well, actually those millions were indians.
Not all of them. Colonizing a new, wild land is a lot safer than living in a land when germ-laden foreigners who view you as savage heathens, but not by all that much.
The problem is that there is nothing that warrant a Martian colony, we got plenty of water, iron and hydrocarbons on earth. Maybe automated asteroid mining, but that's it.
Once we start to run low on terrestrial minerals and hydrocarbons, extracting similar or the same substances from extraterrestrial sources will become quite profitable. And how do you make an asteroid mine 100% automated without making it a machine worthy of a science fiction B-movie plot?
Besides, there's a resource in various places in space which we're running dangerously low on on Earth...space.
Not intended to be a joke. We need more housing? We're out of space (to build houses). We need more power? We're out of space (to make a nice, sustainable power plant). We need more food? We're out of space (to grow crops). All of these can be mitigated with appropriate extraterrestrial habitats. Building on or in Luna makes sense to start--all the advantages of a planetary colony combined with most of those of being in Earth orbit.
*Look at Mars*
Well, humanity will be extinct long before it's worth settling Mars.
Disagree. Humans settled Australia, they can settle Mars. They just need to be a bit more desperate and technologically advanced than Europe was when they settled Australia. After all, if you get stuck without supplies on Mars
or in the Outback--even a kilometer from civilization--you're dying either way if you can't make it that last kilometer or be rescued. The only difference is how and how fast, and thirst can be a swift killer in the outback...
I'm not saying we should not settle Mars. Just that you'd have to be foolish to think it's a worthwhile economic goal.
Doubtless John II thought the same thing, but Columbus went to America (albeit unintentionally) anyway. Doubtless the same question was raised for centuries. "The Conquistadores haven't found any gold; is it really worth it to keep sending them?" Despite all of this "wasted" money, America eventually became an economic powerhouse. Look at those early years of American colonialism, and compare that to a primitive Lunar or Martian base. Now imagine the latter advancing along a pathway similar to the US's, and see where it is no...in the Cold War-equivalent time.