Before revision: Origin "Jobsworth" is a British colloquialism derived from the phrase "I can't do that, it's more than my job's worth" , meaning that to do what is requested of them would be against what their job requires and would be likely to cause them to lose their job.
After revision: Origin "Jobsworth" is a British colloquialism derived from the notion of something being asked of one a work environment being too great to risk their job over, as in, "I can't do that, it's more than my job's worth"