This is not by the way a specific criticism of Krugman (though I do think too many people, including Krugman himself, wrongly think his Nobel Prize for trade theory gives him expertise in every other subject he pontificates about).
As usual, the non-doers (commenters or critics, places like the NYT) have little perspective on things that can change the world. It's up to us in tech to always have that bright-eyed optimism for what is possible, because we're the ones building it day-in-day-out. Observer critics don't really have a place in this, unless that criticism is coming directly from folks who are meant to be the initial customers/users of technology.
[0]https://www.laphamsquarterly.org/revolutions/miscellany/paul...
It'll obviously happen at some point, but they were very wrong about the timing.
There's probably lots of examples on the optimistic side too. AI probably counts there.
Is there any technological opinion people had in 1972 that would be considered embarrassing by today's standards?
The only thing that comes to mind is that Simpsons quote: "I predict that within 10 years, computers will be twice as powerful, ten thousand times larger, and so expensive that only the 5 richest kings of Europe will own them"