I'm going to speak from my own experience, which is that of an attorney who didn't really know about federal job opportunities until I was almost through with law school. I think some of the plusses and minuses of federal work (on the whole, there are far more plusses in my experience) might hold true for members of other professions: for example, engineers.
Oftentimes one gets to a certain stage of career development where the worry of "can I get a job at all?" is accompanied, or replaced, by "can I get a job that has any meaning to me?" As an attorney joining the Bar, I knew I would be able to find a job, but I worried that I wouldn't get one that would enable me to both a) make the kind of contribution I wanted to make to society, and b) enable me to have work-life balance (this is a code phrase that law students use for "not wanting to spend the best years of their life chained to a desk every weekend doing document review, in the name of maximizing billable hours.")