Sound and Sense
The speaker definitely has a bit of an ego. He's out to teach us what makes a good poem, and he doesn't mind showing off a bit along the way. Unlike most dudes who go around showing off how cool they are, though, this guy can totally back it up. He takes on the ancients (Greek and Roman poets), imitating them and illustrating that he's just as skilled a poet as they were.
But our speaker is more than a poet; he's a critic as well. Because of this, we like to call him the poet-critic. He has a public voice, not a private one, because he seeks to intervene in the affairs in the world, like the current conversation about the rules for poetry. The speaker seems to be on a holy quest to rid the world of bad poems, or, at least, to show the world exactly why his are better than everybody else's.