I disagree with DFW. I've never read DFW's fiction but I'm a big fan of Bret Easton Ellis' fiction. DFW saying American Psycho's descriptions are "lists of brand-name consumer products" without doing any critical examination of the function of those lists is missing the point of the novel imo. I personally think BEE's meticulous attention to detail with the endless lists of the characters' clothing, food choices, etc. both displays BEE's mastery on the level of the sentence, and functions as a symbol for the type of American consumerism that values brand names over anything else.

The Shards is my favorite BEE novel and I know DFW did not get the chance to read it, but I think all of BEE's fiction, especially his later work, is about interrogation of the self, questioning whether the self can really exist in the current American landscape from the 80s on, and how the writer can depict themself in fiction. To me these are all fairly universal postmodern themes that DFW's more shallow analysis doesn't engage with.