The "Linked Lists" chapter from "Programming Interviews Exposed" begins:
"The deceptively simple linked list is the basis for a surprising number of problems regarding the handling of dynamic data. Problems about efficient list traversal, list sorting, and the insertion or removal of data from either end of a list are good tests of basic data-structure concepts... Their simplicity appeals to interviewers, who want to present at least two or three problems over the course of an hour-long interview... You can write a relatively complete implementation of a linked list in less than 10 minutes, leaving you plenty of time to solve the problem... In addition, there is little variation in the way linked lists are implemented, which means that an interviewer can simple say "linked list" and not waste time discussing and clarifying implementation details."
I always look at that stuff and I ask about it during interviews, but I still ask general technical questions. Sometimes the candidate's contribution to a project is nothing more than writing the README file.
No one ever looks at it. I'm starting to wonder why linked lists are so important to employers.