Trust. If you want people to want to work for you, you shouldn't be seen getting rid of people for no reason at all.
Source: I just left Red Hat unrelated to the layoffs.
In my estimate it takes an intermediate software engineer "new hire" about 6 months to get to a point where they can add measurable value and it probably takes 2-3 years to maximize their experience/contribution ratio. From then they can still ramp up but it's a longer curve.
Rehiring some random person, if you already had a good person in the role that you're firing, is just plain dumb.
Likely most CEOs do not understand that.
On the other hand, keeping a person that's not a good fit is just as plain dumb. That's true regardless of the state of the economy but doubly true when times are hard.
A typical ROI on new initiatives in tech can be anywhere from 2 to 5 to even 10 years. I.e. companies that are going to be successful some years from today need to be working on that event horizon. Companies that have laid off less or no or "token" amount of people, while maybe also still hiring (there are companies like that), are likely those that think like that.