Doesn't seem like such a huge deal, right? We mean, Catullus was around back in the day, too. Think about it, though. These love poems—the Song of Songs—got put in the Bible. We're used to hearing about marriage, family, and babies in the Bible (often with a little political or social turmoil thrown in), but straight up love poetry? Not so much.
P.S. You might notice that we said love poems, plural. It's tough to verify, but people are pretty sure that Song of Songs is actually a collection of poetry, not just one long poem. If you read it with that in mind, you might see things a little differently. And that explains why we can never tell who's talking.