“Mail & Guardian” has a commentary by Tim Lott called “Whatever happened to literary love?” In it he says that stories about love are becoming rare, though they were once the standard of great literature.
Richard Curtis, screenwriter of “Four Weddings and Funeral,” “Notting Hill” and “Love Actually,” brings the point home:

“If you write a story about a soldier going AWOL and kidnapping a pregnant woman and finally shooting her in the head, it’s called searingly realistic, even though it’s never happened in the history of mankind. If you write about people falling in love, which happens a million times a day … you’re accused of writing something unrealistic and sentimental.”

I am assuming Lott means love as the sole plot for a story, because tons and tons of books have a love relationship as a part of it. (Heck, you could easily argue “Fight Club” is a love story, but I’m sure that’s not the kind of book he means.)
A good love story is hard to write. You are writing about a universal experience, so it has to resonate as true. But you also don’t want to bore people with cliches. You want to say something new. You want to be original.

The New York Times best seller list is topped by mystery and suspense books. Was there a time when it was topped by romances?

-Marcia