> It's so popular because it's the only data structure that is easy to use in C.

Is this reasoning really true? A quick search reveals the availability of higher-level data structures like trees, flexible arrays, hashtables, and the like, so it's not as if the linux kernel is lacking in data structures.

Linked lists have a few other advantages - simplicity and reference stability come to mind, but they might have other properties that makes them useful for kernel development beyond how easy they are to create.