This text generally did what it set out to do: provide a good overview of human resource management in a public work environment. However, much as I may sympathize with the authors' point of view, it too often devolved from an education text to a polemic, always taking an explicit pro-government worker position.
It's a missed opportunity. Certainly a manager needs to understand, appreciate, and value their employees. But managers must also be capable of understanding the political environment in which they find themselves, which yes, may be actively hostile. Excoriating political actors for treating the civil service poorly doesn't help a future manager do their job better. It provides no tools. It holds no lessons.
"They suck" (in so many words) may be cathartic for the authors, but it is insufficient for a book that purports to teach current or future managers how to be better at their complex job.