If it's a highly sought-after high-status job, there may be oodles of takers for every getter. The sheer amount of competition may force their hand, and the "it's a job" may be simply a case of this.
Another possibility is the sunk cost fallacy. If the job requirements are strict enough and the people who eventually get the job have had to sacrifice enough getting there, that alone may be enough to get them to stick with it. Add some social pressure for spice as desired. Stir with self-deception and serve with verbal rationalizations.
The other day, someone did something I didn't expect. It was something many people have done before; something that I thought of as very normal, but that I in no way understood and had not predicted.
As I said, this had happened many time before, so I wrote it off as "me not understanding people" or "people are weird" for a second, like I usually do, before realizing that "bad at" really means "lacking basic knowledge", which I had never realized before.
And then I thought "I should ask someone who is different from me why people do that, and eventually someone will have an answer."
But many people will have many more questions like this. So, what have you observed people doing time and time again, but never understood? Or something that you only understood after a long time or asking someone about it?
And can Less Wrong tell us, not necessarily why (I for one can make up evolutionary psychology fairy tales all day if I want) but what conscious thought process occurs behind these events?