Bizarre. People expect either (a) company management to be completely clairvoyant about what the future will hold, or (b) when their best estimates about the future change, I guess folks expect management just continue charging ahead until their company goes bankrupt.
I also totally disagree with this statement, if you're implying that you think good CEOs should layoff as few people as possible: "I always felt that good CEOs (from a culture perspective) make it clear that in times of trouble, the first priority is not the business, but everyone working there."
If anything, I think good CEOs are clear about making tough, painful decisions, and they make them quickly and move on as fast as possible. There is nothing worse than everyone seeing the writing on the wall (e.g. lots of people with not enough work to do), but feeling that management is paralyzed by fear to change it.
What's going on is really not that complex. Companies (and MANY companies, certainly not just Klarna), planned for number of employees based on estimates about the future state of the world, and that future state of the world turned out to be drastically impacted by all the events mentioned in that letter.