In addition, he comes to this from only an American experience. This is not a symptom you only see in the US. It's saccharine in many places. That said, saccharine or not, it does have a purpose as much as any other line of questioning. In other words, passion, love, whatever, while they may or may not be an indicator of how well someone will execute their job --the main purpose of such questions, in my mind, is to see how well prepared you are for something you can expect.
In other words, it's not that they expect a sincere answer or they are trying to torture you and see how you wiggle yourself out, but it's rather to gauge how adept you are at preparation. You know the questions is coming, yet, did you take the preparation to come up with a sensible answer. That is the function of the question.
On the other hand, if we were to take these questions literally, yes, then they are quite silly expectations. I have had them at just about every professional job and they are absurd. But we know it's all part of meta-communication. Do I wish it were simpler and didn't recourse to this style of communication, yes, but I think I understand its function.
On the other hand, I do enjoy people regarding their job as an act. A role to fulfill. When we understand our jobs to be essentially a role to fulfill, it's liberating in a way. It's no longer you, it's your job personae. Compare service workers in Japan and Europe. Which ones deal with their situation better? I believe the Japanese worker has a better understanding of the situation. They put on their persona and take it from there. To see it any other way is to see an actor performing a dark character and feeling bad for the actor. No, to the actor it makes no difference. It's an act.
That said, I've come across very good service workers in Europe as well. They very well understood their function and were happy to play it out.