Yes, we could do as you say. The problem is that it would default to the decision that our species would die. There are too many things that we know can cause planetary level extinctions being intelligent or advanced does not protect us from these things. I disagree with the way the three billionaires you reference in the article are approaching the problem of getting humanity out of our cradle, but at least they are trying something. The idea of moving people into space and other planets isn’t for the specific people moved, the companies, nationalities or faiths are all unimportant in this. Either we move into space or our species has a lifespan determined by the next extinction event on the single planet where we are living.