Well, yes. The kernel _now_ has all kinds of data structures, but you can look at the documentation from 2006 and see the horror of even the simplest rbtrees back then: https://lwn.net/Articles/184495/

A simple generic hashtable was added only in 2013!

> 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.

The main property is that it's easy to use from C. Think about growable vectors as an exercise.