I agree with this. There are ~400 billion stars in the Milky Way and about the same number of galaxies in the
visible universe. That's roughly 1.6 x 10^23 stars in the visible universe (160,000,000,000,000,000,000,000 stars). Something like 2/3s of stars are binary/trinary/more, and for the sake of argument we'll say that any planets orbiting these systems are unsustainable to life (though this is most likely a false assumption, it's best to err on the side of caution).
So, 2/3 of 1.6 x 10^23 = 1.06 x 10^23, (or 106,000,000,000,000,000,000,000 binary/trinary/etc. stars)
That leaves 5.4 x 10^22 "single" stars like Sol (54,000,000,000,000,000,000,000 "single" stars).
Of those stars, about 1 in 13 is a type-G star like the sun, so let's again err on the side of caution and only talk about those stars which are sun-like: which is about 4.2 x 10^21 (4,200,000,000,000,000,000,000 sun-like stars).
Of
those stars, research is showing that about 1/4 of them may have planets similar to the size of earth, which is 1.05 x 10^21 (1,050,000,000,000,000,000,000 stars with earth-sized planets, which are class G sun-like stars).
The odds of winning the Powerball lottery are 1 in 195,249,054.
That means if each earth-sized planet orbitting a sun-like star had a random Powerball lottery ticket, we can expect ~5.4 x 10^12 randomly winning tickets (5,400,000,000,000 Powerball winning planets if each has just one ticket).
The odds of drawing a Royal Flush in the first hand if you draw only 5 cards from a thoroughly shuffled deck is 1:649,739.
That means if each earth-sized planet orbitting a sun-like star had one deck of shuffled cards and someone drew the top 5 cards, we would expect 1.6 x 10^15 of them to draw a Royal Flush (1,600,000,000,000,000 Royal Flushes if each earth-sized planet orbitting a sun-like star had a deck of cards).
Keep in mind:
1) This is only considering the observable universe; if inflationary theories are correct (and we have much reason to suspect they are) then the universe beyond the visible universe is larger compared to the visible universe than the visible universe is compared to planet Earth... that's a lot, lot, lot,
lot more galaxies and thus a lot, lot, lot,
lot more earth-sized planets orbitting sun-like stars.
2) I assumed that life couldn't form around binary star systems but that assumption may well be ill-placed: such systems can be extremely stable, and some are known to have planets.
3) I assumed that life might only develop on Earth-like planets, but that may not be the case. Carbon-based life may well be able to develop in different environments (consider the extremophiles we have on Earth), and carbon chemistry isn't the only chemistry system thought to be able to support life. Ammonia-based life would thrive on different kinds of planets than carbon-based life that we're familiar with (it's hypothesized ammonia-based life would thrive on very cold worlds with much higher pressures due to the nature of the chemistry). There's also the possibility phosphorous/nitrogen-based life, silicon-based life, cyanide-based life, and so on -- all which would thrive on different types of planets that I've left out of my calculations.
4) I assumed that only class G stars like Sol could sustain life, but taken in conjunction with the possibility of different chemistry-based life it may not be true that a star must be like Sol to sustain life. In fact, here is a theoretical diagram of different "Goldilocks zones" for carbon-based life for star types other than Sol's class G type:
Then keep in mind that the habitable zones would be different for different chemistry-based life.
Yeah... I'd say that the odds are astronomically in favor of life developing even if the odds of life developing are astronomically low (which they may well be).