Poor performers are demotivating, yep. The challenge of a manager, and really, the whole management system, is making reasonable efforts to get employees back on track, if that's possible. I mentioned the life events thing because it's real. Sometimes a PIP (performance improvement plan) gives people a jolt and gets them back on track, sometimes not. It's the job of management to separate true under-performers from temporary ones and to find the best roles for members of the team.

What Zuck wrote had none of the nuance or understanding that one would expect of someone with even a moderate amount of experience managing people. It's true that firing people is hard, which is probably why these companies should not have focused on eating the world so voraciously for the past N years.