Expecting somebody to know what a hash table is and understand the time complexity of inserting and looking up elements is fair. Expecting them to build one from scratch on a whiteboard is just ritualized hazing.
I don't see anyone mentioning requiring one to build all these data structures from scratch. I'd agree with you that this is a less useful exercise for interviews, in particular front-end interviews, but I don't think it's fair to assume that this is what the poster above meant. Only "basic knowledge" was mentioned.