Having seen, as a contractor, the internal operations of a number of departments and agencies, my observation is that the federal workers who genuinely do work worth the name are encountered with needle-in-haystack frequency.
On the other hand, federal employees who are there to do nothing but milk the system for maximum personal benefit and who cares about the rest of the world are overpriced at a dime a dozen.
I will say, as a federal employee, that I work more than the 40 hours per week that I am supposed to work (no overtime for me, either), and I feel like the undone tasks are piling up, waiting to come down like an avalanche on my head. Most of my people work quite hard (and I cannot allow them to work overtime the way I do).
Although we work hard, I think that a lot of the work is unnecessary--it is the result of regulations, of having to take over 100 hours of training every year, of having processes and procedures that make what seem to be simple tasks hopelessly complicated.
I blame computers for a lot of it. Most of my day is spent answering and sending emails. This seems to be how things are done these days. In the pre-computer age, it seemed like paperwork was not nearly as cumbersome or prolific. Yes, computers make things easier--so there are more things to do that more than fill any time the computer might have saved.