> The linked list is such a fundamental piece of technology that you never have to implement it.

Is this a good reason not to ask it in an interview?

I'd expect any competent software engineer to be able to implement a linked list without too much trouble. It's maybe not a great interview question (depending on your point of view, you may not consider it to contribute much positive or negative hiring signal), but I don't consider it a "gotcha" question the way a lot of people seem to.