"Very very few people who don't believe in the mission of whatever their organization does make it very long in government. Government organizations are such a political and bureaucratic nightmare that you need to believe in what they do to be able to see past all that. "

That's simply not true. Go to DC and you will meet a lot of dedicated and highly qualified people working at agencies. And they stay around. The real problem is Congress and some of the media that just scream "government bad" and "deep state" instead of doing their job which is to give the agencies guidance and fixing problems.