This book captures a frustrating problem that applies in theory to many different fields in the professional world, but especially computer and technology fields where software development gets done. The idea of a 'man-month' is a little like the term 'man-hours,' because it attempts to do the same thing. Instead of viewing projects by how the management thinks they should go, and how long they think the projects should last, employers should ask engineers how many months it could take.
By being realistic about these time expectations, the true hope is for less toxicity in the industry. One should appreciate the difficult task of being an employer. Of course no one wants to hire an incompetent engineer, but there are a ton of incompetent engineers fighting for jobs, sometimes lying on resumes, sometimes learning more on the job than the employer might hope. Expertise is hard for certain employers to predict, especially when the person in authority doesn't really understand computers.
So, employers are forced to use their instincts, but they are often completely wrong about the technical, hands-on difficulty of a task, so the task becomes more about social management than technical management. Ultimately, the goal of this Mythical Man-Month is to spare engineers of the paranoia that comes from harsh management, which typically coincides (unfortunately) with difficult projects, because those are the ones that can frustrate an office.
