Fruitcake is a Christmas tradition for several reasons. Firstly, it is a dense, rich, and delicious treat that is well-suited for being served during the colder winter months. Additionally, it is a very long-lasting dessert, which makes it a great choice for being served during the busy Christmas season when there's so much to do and little time to bake. Lastly, it is often seen as a symbol of tradition and the passing down of recipes from generation to generation, which adds to its appeal as a holiday dessert.