Final answer:
The constructor of a LinkedList class is often empty because its initial state simply requires no elements, represented by null head pointers in singly or doubly linked lists.
Step-by-step explanation:
The constructor of the LinkedList class is often empty because the initialization of a new LinkedList doesn't require any preliminary setup besides creating the list itself. A LinkedList is a dynamic data structure where elements are linked using pointers, and so the 'empty' construction merely establishes an initial state where the list has no elements. This is usually represented by setting the head of the list to 'null' in a singly linked list, or both head and tail pointers to 'null' in a doubly linked list. As elements are added or removed, the list structure and pointers are updated accordingly.