I think we do a disservice when we adopt an either/or perspective. Federal employment is both a calling, and a job (and occasionally a bitter disappointment), depending on what sort of job/role one is in.
We too often forget that not everybody is steeped in critical policy work or serving the public directly, or lowering themselves out of a helicopter to rescue someone. A significant portion of the federal workforce, no matter what the country, are involved in doing the very sorts of jobs they might do if they were working for an insurance company, or in accounting for a large retail chain, or for the local school board.
Perhaps beantown cult favorite Jonathan Richman (and the Modern Lovers) said it best when they declared in song several decades back:
Well we've got alot alot alot of hard work today
We gotta rock at the government center
Make the secretaries feel better
When they put those stamps on the letters
And they got alot alot alot of great desks and chairs
Uh huh, at the government center
We gotta make the secretaries feel better
When they put those stamps on all those letters
That is not to denigrate the work itself whatsoever, but there ARE a lot of folks working "for the feds" who are happy and proud to be part of a larger organization that serves the public interest and has such a long and noble history, but who were basically looking for a decent paycheck, with decent working conditions, doing work they weren't ashamed to tell their grandparents they did, for an employer who wasn't about to outsource to Bangalore or Jakarta. The overall mission was not their basis for job choice (or even work performance) but simply something nice and appreciated that comes along with the job.
Some folks DO make it a point to have their job choices dictated by selected career paths that depend on serving their particular "calling", but not everyone does, and it isn't any badge of shame to simply do one's job well, treat one's co-workers with kindness and respect, and be appropriately compensated for it.