So like there's definitely romances out there with only one POV. Twilight, which isn't genre romance, but is certainly a love story, is a story where the way it's told works well because it's told from one character's pov, and if you got the other character's pov, the mystery would be revealed. So if you feel your story is one of those romances that works better from a single POV rather than two POVs, you could certainly go that way.