There appear to be two main reasons. First, since theory itself intermingles ideas from philosophy, linguistics, history, political theory, and psychoanalysis, why should theorists worry about whether the texts they're reading are literary or not? For students and teachers of literature today there is a whole range of critical projects. topics to read and write about-such as images of women in the early twentieth century where you can deal with both literary and non-literary works. You can study Virginia Woolf's novels or Freud's case histories or both. and the distinction doesn't seem methodologically crucial. It's not that all texts are somehow equal: some texts are taken to be richer, more powerful, more exemplary, more contestatory, more central, for one reason or another. But both literary and non-literary works can be studied together and in similar ways