It is, arguably, the biggest of them all?
Think back to Adam and Eve. Why did God make Eve for Adam? Because he was lonely and needed company. I think men and women alike (although most men won't admit to it) enjoy a good romance now and then to give them that surge of adrenaline or emotion that they need to satisfy that same desire. Even in a great relationship, which I am, a great romance takes you back to that moment when you first met your loved one and reminds you of what you love about love all over again.
We were designed to love one another ... so no matter what genre is out there there will most likely be a love or romantic component in there somewhere.