As a lot of people have noted, the test has nothing to whether you'll actually work on a Sunday (most people don't). Instead, it's about whether you'd go out of your way to be around that person. Like it or not, we all spend lots of time around all of your coworkers, and I for one want to work with people who make me happier for it.
I don't think these problems are actually easier in other fields. Both my parents are physicians, and over the past few years they've been having a lot of trouble hiring the right coworkers. Many of the ones they've ended up with have either ended up not being very good, not being that pleasant, or not being very invested in the role. Ultimately these hiring mistakes have caused a ton of friction and problems for the entire staff, and it's pretty clear that there's something wrong with the initial hiring process.