Because they're pretty much babby's first data structure. When I was a kid and I needed to store the bag o' sprites for my first Windows 3.x game engine (don't ask), I had the BRILLIANT idea to store pointers to the previous and next sprite in each sprite, thus creating a doubly linked list with no formal CS experience, nor exposure to that particular data structure. If somebody knows thing one about programming that isn't dinking around in BASIC, it's going to be linked lists.
