No company hires just because. They have a plan and need people to execute it. If those people do their jobs well and still the company fails, then logically, you would keep the workers and replace the management. But it never seems to work like that.
Say that IBM had a plan that involved hiring 5000 pastry chefs. They did their jobs excellently, but it turned out that nobody wanted servers that baked doughnuts. Fire the management who came up with that stinker, or not, either way--but what good will come in keeping the 5000 pastry chefs?