I think someone's ability to understand and explain recursion like am a child is very undervalued. It's not about testing whether you know the base case or the fact that you write less lines of code in recursion but the fact that there is a built-in stack for you to use without creating one.

What are the practical applications of recursion though ? Other than sorting and DFS ( well even DFS can be done iteratively with stacks ). I'll be curious to know.

I find testing for HashTable/HashMap knowledge to be far more practical than testing for LinkedLists simply because you can't escape HashTables in today's world.