I really get the feeling that many companies are just blindly doing whatever other companies do. One starts large layoffs, and suddenly everybody is doing it. At other times, when one goes on a hiring spree, they all go. One tries to reduce salaries, they all do. One pays enormous bonuses, and they all do. It's like CEOs aren't really thinking for themselves, just copying whatever the market does.
The thing is, in a lot of the cases, the companies preserving cash by laying off workers aren't really saving a significant amount of cash, compared to the amount they have on hand. So, it turns into some sort of lemming behavior.