The idea that improvements and changes in technology inform ethical choices is important. If there had been no industrial revolution, or if it had taken much longer to arrive, how much longer would the abolition of slavery have taken? Machines able to do the jobs of slaves made it much easier for people to become abolitionists. There are more examples in the book but this is the most poignant one.
The author also makes the important point (which many others have made too) that no matter how enlightened we think we are, we are doing things now that people in one or two generations will be aghast at, the same way we are aghast at slaveowners. "At this moment, society has a surplus of Avenging Angels and a drought of Ghandis," he says, accurately.
But the book is annoying. Its style is painfully casual, with lots of "BTW" and "BFD" and little factoids or cutesy asides which are right-justified in a different font. (All of this from MIT Press.) It is poorly edited with missing words and extra words ("clueless as to just what just happened"). Sentences that may have been written when drunk, like "Pharma often it abuses and price gouges." I could only gasp in horror when he quoted Susan Sontag.....but sourced it to a Goodreads quote! People, no. One-third of Goodreads quotes are made up.
He claims American test scores have been flat, but he quotes someone who only looked at 12th graders. (Test scores in math and reading for 4th and 8th graders, the other two groups tested on the NAEP, have been steadily increasing over the same time period.) He writes that Al-Qaeda banned plastic shopping bags - but even the article he links to doesn't claim that (it was the terrorist group the Shabab, which the article says "has claimed allegiance to Al Qaeda") and the article is by Rukmini Callimachi, so buyer beware!