Some books are clearly works of literature, and others are clearly intended to appeal to lovers of philosophy or politics, and there are also clearly works which are intended to operate as a means to philosophical or political inquiry whilst being framed as a literary work (a venerable tradition). There are, however, relatively few novels which can immediately and effectively communicate the myriad of positions within a dialectic framework (you might immediately think of Orwell's '1984' or Tressel's 'The Ragged Trousered Philanthropist), and 'The Fountainhead' is an attempt by Ayn Rand to produce a work that falls within this latter tradition.
As a work of literature, with the primary aim of communicating the human within the structures and framework provided by Rand, this novel establishes the template replicated in her other major novel 'Atlas Shrugged'. Each character is necessarily intended to be representative of a particular position within the dialectic that Rand explores, unfortunately often resulting in superficial, stylised characters lacking the complexities essential to maintaining interest in the narrative.
The most obvious example of this approach is the rendering of Rand's ideas in to large tracts of text which are meant to be representative of human speech - but the effect merely highlights the superficiality of Rand's commitment to the novel as an artistic literary form. This can be further seen by the predictable parallels existing between 'Atlas Shrugged' and 'The Fountainhead' - the apparently independent and wealthy female, perceived as emotionally detached yet sexually alluring, the iconoclastic male, prepared to suffer apart for the values which remain ignored or misunderstood by his fellows. There is also the notable fact that the apparent freedoms enjoyed by the lead female in both 'The Fountainhead' and 'Atlas Shrugged' are predicated on a position of inherited wealth and security, founded on the unquestionable and inherently moral excercise of capitalism.
As other reviewers have noted, this artificiality, this attempt to provide amplified ideals by way of character, largely fails to engage a genuine interest in the reader. These are not characters that you would wish to meet, even if you were sympathetic to 'objectivism'. Such is their dysfuntionality.
Perhaps, of course, this is entirely the effect that Rand intended. These are hyper-characters, expressions of Rand's ideals whilst others represent all that she loathed and despised. Perhaps Rand never intended to produce a naturalistic novel or text, but given the apparent effort to place the events described within a recognisably real and familiar world and time frame, this is not likely to have been the case.
A further criticism can be extended to the size of the text, owing more to the verbose than the necessities of analytical philosophical exploration. Points are repeated, with the effect that the reader is likely to feel harangued as the subject of an extended lecture. Yet the essential substance of Rand's position could be articulated in less than five hundred words; here the reader has to negotiate through page after page of repeated stock descriptive phrasing and language which does little to conceal the paucity of Rand's vocabulary or imagination. For a novel to succeed there has to be more than this!
And ultimately, in my view, this is why the book does not function well as a work of literature. The vacuity of character, the inability to engage beyond the superficial, the purely functional language, these are critical failings in what might be described as the base framework of a book. With such a poor base structure the superstructure of 'Objectivism' (despite its relative ideological simplicity) can not be functionally supported, and for this reason the book fails as a contribution to the art of literature.
This remains the most telling failure of the book. It is difficult to imagine a writer producing such a self-destructive and damaging literary introduction to their philosophical and political ideology.