Traditional Witchcraft is a term that was introduced to refer to the aboriginal spiritual traditions of Europe. There really is no collective historical term that could be used to refer to these traditions, so the use of the term Traditional Witchcraft fit quite nicely. Those who follow these traditional ways are often referred to as Traditionalists.
Unfortunately, in an effort for Traditionalists to define their cultural beliefs and traditions which varied dramatically from those proposed within the Neo-Pagan movement, somehow the term Traditional Witchcraft was also adopted by those who became disenchanted with Neo-Paganism and its Wiccan counterpart. Still others adopted the term Traditional Witchcraft as a rebellious movement against the fluffy bunny goodness and light that seemed to be manifesting itself within Paganism. Of course, this deviated so incredibly from the definition of Traditional Witchcraft and from those who actually are Traditionalists.