Trees and graphs serve useful roles, of course, but calling a linked list just a simpler version is a stretch. It'd be like calling an array a simplified B-tree. The simplification changes not just the implementation but also radically changes the applicability of the result.
except a tree or graph with multiple pointers is similar to linked list with one pointer.
where as a b-tree stored in an array without pointers probably shouldn't be called a b-tree.
or am I missing something?