@Ursula267 One thing to consider is that many people who travel in pairs are not couples, and prefer to sleep separately. For example, picture two hiking buddies out to climb the nearby mountain that doesn't happen to be called Brokeback, or a young professional having a girls' weekend with her mom.
Having a second bedroom adds significant value to the home for those travelers while also opening the listing up to groups of 3. But turning over a second bedroom with each stay adds to your labor and laundry cost, so the overall rate should go up accordingly.