my teacher richard rorty used to argue - with typical provocativeness - that philosophy was "merely" a literary genre: no more some sort of precise access to truth than the novel or lyric poetry. well, it is certainly, among other things a literary genre, or several: a way of writing books. one interesting feature is that it is basically polemical rather than narrative, which i think is important: the basic structure is premises-conclusion rather than, you know, set-up-climax-denouement. 

but one thing to think about along these lines: how good a philosopher you are isn't correlated to how good a prose stylist you are. philosophy has had some great stylists: perhaps plato (though i have some reservations), hume, kierkegaard, nietzsche, quine. but it has had some truly labored, infelicitous, or perversely hostile stylists: aristotle, aquinas, kant, hegel, rawls. philosophical quality, or at least reception, definitely does not correlate with the quality of the writing.

in fact - and this is as true now as ever - excellent writing, or a light touch, etc. are regarded with suspicion: there is not enough seriousness, not enough density of system, not enough jargon-driving precision to really do the conceptual work. in a way, the infelicity of aristotle's prose (a bit of a problem because the books seem to be largely lecture notes) is part of its scientific status, its dedication to truth rather than mere pleasure. and i hate to say it, but the obscurantism of a hegel or a wittgenstein or a heidegger is a mark of their profundity: extremely dense or tenebrous prose means genius, in a way. (heidegger has his amazing moments as a stylist, however.)

figures like kiekegaard are great masters in philosophy, but not quite perfectly profound. at any rate, if philosophy is a literary genre, it has its own myriad peculiarities. you certainly wouldn't say of a poet, for example, that she was a good poet but not a particularly good writer.