What does forrester mean when he tells Jamal, "people are always talking about my book but never say anything about it"?

Forrester is not a social person. He does not leave his apartment because he does not like contact with people. There is something about Jamal that he finds intelligent and valuable. In this quote, Forrester means that he does not think the people who are talking about his book are saying anything worthwhile. They only comment on the ideas and analyze the literary merits of the novel rather than engaging in an intelligent conversation about the themes of the novel.