[dmreedy]

I think that's part of it, but there's also the facet that a lot of people just...don't care. Families, hobbies, etc are all valid reasons to live for outside of your employment. If the majority do just enough to get by and not get fired (which, as pointed out in other comments, is a pretty low bar in the government, as it is in many large large companies), then the system eventually converges into a sort of homeostasis of mediocrity, which is viciously self-preserving [1].

---

[1] these together are pieces of Yudkowsy's revision of Hanlon's Razor: "Never attribute to malice what you can attribute to an enormous complicated System full of conflicting incentives getting stuck in a weird equilibrium. When that weird equilibrium is crushing people in its gears... We see a broken watch and infer a Watchbreaker."