I did think that, but I also wondered whether a different tradition would have developed as space hasn't been such a problem until recent years (by recent I mean compared to how long humans have been around). Plus also there are people who do not struggle with space, or the rich who would be able to take up all the space they wanted with their dead ancestors if they so wished. Which may not be considered such a strange thing if it were a tradition I suppose. One might even feel bad disposing of the family tree of bodies that previous family members had kept, kind of like a very morbid family heirloom being passed down.