True, but he includes Nietzche - while Nietzche's literary status is beyond question, they are not so memarkable other than the fact that they were very influential. J.S. Mill's On Liberty is also included - not being particularly appraised for its literary status as much as its influence on all liberal thought.

Marx was arguably a literary genius in the same way Nietzche was, and influential in the way J.S. Mill was. He should be on the list by both accounts of what the list should contain. Not to mention, Bloom includes many authors who count Marx among their primary influences, like Walter Benjamin, Brecht, Orwell, Levi-Strauss, Sartre, Camus, and Bataille.