> The idea that Ayn Rand is a philosopher in any meaningful sense is very debatable.

Its not entirely unfair, though "polemicist" is more accurate than "philosopher"; moreso than to say that Ayn Rand is worth reading in any meaningful way, at least.

> She was an author of fiction, like Terry Pratchett.

In terms of the works that make this a reasonable statement, I would more say she was an author of religious (or, if you prefer, ideological) polemic packaged as long-form fiction, like Tim LaHaye and Jerry B. Jenkins.