Western Heritage.

I would just like to comment on the differences I have seen thus far in every day literature, and the college level text book "Western Heritage, AP edition". In literature, the language, wordplay, all make the material you are reading a little bit more interesting, and has the ability to capture the imagination. The textbook... is incredibly dull. One is contantly glancing at the page number, rushing to finish the required reading.
Here is my question:

Why can't they add literary aspects into textbooks? Why do textbooks have to strictly contain information and high comprehension babble as word choice? Why aren't metaphors used, why don't they go into depth about the characters in history they describe. Reading this could be made so much more interesting, and I believe many would agree with me when I say that the material would have a better effect on students if we could get an idea of what battles were really like, how the kings and queens across Europe processed information. They book would be longer, but students would actually retain the information they read, and the material wouldn't seem as forced as it is right now.