Wallace reproaches Ellis for failing to offer any alternative, or any insight in addition to what he mocks and ridicules as the 'darkness of the time'. This critique is directly in line with Kierkegaard's view of irony, and the need for realizing a positivity in its wake.
Thus American Psycho falls prey to the same attitude of which it shows us the extreme escalation, namely the total negative irony of the aesthetic life-view. This is not to say that the novel or Ellis somehow 'condone'--if it even makes sense to say such a thing--the violence that it portrays, but it is to say that the novel cannot truly criticize the attitude that lies at the root of these escalations, since its only way to do so, is to desire from its readers the same thing it portrays in its main character: endless irony.
The fact that Ellis's novels only ridicule and ironize, and are unable to formulate any meaning or value, shows us the underlying aggravation of the postmodernist view of language and fiction (and the formulation of meaning therein). Ellis regards the meaningful description of the world, whether it is seen as 'reality' or as 'fiction,' as a simple impossibility. His works do not display a search for a way around this problem; they merely ridicule all attempts to find a way out, as well as the excesses that inevitably follow from the lack of a way out. There is, indeed, no exit.
see note 199