Layoffs are a failure of management. If the company has not been executing a long term strategy to respect people and manage the system to continually improve, manage for the long term, working with suppliers... it might be they have created an impossibly failed organization that cannot succeed in its current form. And so yes it might be possible that layoffs are required.
At exactly what point some layoffs are necessary and how much other stakeholders are squeezed to avoid layoffs is not simple to answer (just as employees are squeezed to avoid suffering by other stakeholders). I think to have any pretense of good management systems while resorting to layoffs management must say what specific failures lead to the situation and what has been done to fix the system so such failures will not re-occur. Those explanations should seem to be among the best applications of 5 why, root cause analysis, systems thinking, planning... that you have seen. Layoffs should be seen as about the most compelling evidence of failed management. Therefore explanations attempting to justify the layoffs have as high a barrier to overcome as any proposed improvement to the organization/system.
continue reading: Bad Management Results in Layoffs