I find it rather humorous that two exo planets, even if supporting life as we know it, the author posits that both due to being a couple billion years older could have evolved life more advanced than our own. I think that watching too much Star Trek could be responsible. The notion that intelligent species are inevitable in the evolution of living organisms is a bit far fetched given that homo sapiens are a one in a trillion shot on this planet, alone, compared to all that has evolved.
And a major event that undid an equilibrium that spanned millions of years was needed to pave the way to us, and would have endured for millions more had the mass extinction event not occurred. And without the sudden stirring of the evolutionary pot, dinosaurs would never have come close to evolving into intelligent life.
Plus how many other potential trajectories might life have evolved into were the event that lead to us having evolved been one percent greater or lesser in impact? Myriad other changes in the evolutionary path could have occured and it's not rational to assume that they would have lead to intelligent life when no such trajectory existed previously.
You could have billions of Earth like planets and still not be certain that intelligent life would come about at any time in the planets existence. The Fermi Paradox is spot on, IMO. If indeed we were the inevitable outcome of evolution, the Milky Way would be littered with it and the galaxy would be an orgy of signals that were obviously the creation of intelligent life. But there's nothing yet and I doubt there will be any time soon, as in we are still in existence.
And I believe human kind would be better served by understanding how truly precious and very possibly unique we are. We might be better to one another and take preserving this planet more seriously. Colonizing Mars is absurd. Try colonizing Antarctica. At least it's got breathable air and ample sources of fresh water. Billionaire's folly should not cloud or reason, much less science fiction nonsense, especially among our scientific community.