I'm no fan of Zuck, but what did he do in this case but create a company that provided a lot of jobs, then made some bad forecasting decisions that resulted in losing some of those jobs?

Plenty of CEOs have blamed the economy, the pipeline, the customers, the competition, the weather, etc. He's accepting he made some decisions that over-extended the company and as a result they have to make difficult layoffs. (Which has happened at every company I've been a part of and is happening at many other companies just in the past week.)

There is always employee turnover in business, this is normal and employees are never guaranteed lifetime employment or the CEO quits too, that's silly. Standard part of all contracts with US companies is an at will clause stating that employees can be terminated at will without reason except for an illegal one. The people losing their jobs should thank Zuck for the time he did employ them, the chance he took on them, and also for the generous severance packages he's giving them during a general economic downturn.

Why? What if your decisions lead to hiring 100k, and -10k in a downturn. Is that a net good or not?

What if you want to hang on, and hope to hire more in the future?