I think you're right, there's probably no strict dichotomy. Figurative language can be precise, but it takes mastery. Poetry is a lot like philosophy in the sense that everybody thinks they can just do it, but the truth is, you probably can't, and that's because it takes a lot of work to do well. Not too many excerpts of philosophical writing are likely to be anthologized in Norton, and for good reason. When I studied poetry, I only ever ran into one philosopher, Nietzsche, and that was owing to the high degree of control he demonstrated with many of the figures of speech (or at least his English translators).

That said, figurative language, used well (and probably used sparingly in a philosophical context) can be effectively employed as a kind of short-cut to sense, a good method to get your audience to understand what the heck you're talking about, which of course can come in handy with philosophy, since philosophical concepts can sometimes be difficult to grasp right away.

This is a typical passage from Blackburn that illustrates what I'm talking about, here discussing moral relativism:

ethical truth is somehow relative to a background body of doctrine, or theory, or form of life or “whirl of organism”. It is an expression of the idea that there is no one true body of doctrine in ethics. There are different views, and some are “true for” some people, while others are true for others.