In "the dark knight", at the end, why Batman doesn't reveals himself as Bruce Wayne to Harvey Dent?

As he does to Catwoman in the second Tim Burton's Batman movie. He could tell Harvey that he is also in pain for Rachel's death and that Wayne Enterprises will use all his resources to cure him, that could save Harvey's life, and also the chance for becoming a villain again in Batman 3. Is it just because Nolan hates those movies or is there an actual good reason for Batman not to do that.