Although hash tables are used internally by libraries, they are not directly used by the application developer. When was the last time you had to hand code a hash table?
Unless you are a library developer, its an example of a task and knowledge that will never be needed. If its something that is never used in that particular job, why ask it in the interview in the first place?
Well, our disagreement is just a matter of miscommunication then.
I never said anything about hand coding a hash table.
I would like prospective candidates for programming jobs to know that there is a thing in their language of choice that lets them make fast lookup tables.
Unless you are a library developer, its an example of a task and knowledge that will never be needed. If its something that is never used in that particular job, why ask it in the interview in the first place?