The porn theory is not really valid. Romance novels vary widely in their emphasis on sex and many have none at all. Those whose primary emphasis is on sex are generally regarded as a different genre, or some regard it as sub-genre, of erotica.
The diversity of genres within the field also belies the claim of formulistic writing. Sub-genres run a wide range including historical, paranormal, contemporary, sci-fi, young adult, time travel (e.g. the Outlander series). Even within certain sub-genres there are numerous sub-sub-genres. Historical romance novels encompass sub-sub genres involving every time period conceivable. The Twilight novels was basically a young adult paranormal romance series.
The questions and criticisms here also reflect typical male bias. Romance novels are no more "fluff" or formulistic than things like Westerns or techno-thrillers enjoyed by men. Murder mysteries are incredibly formulistic and you just know the hero is going to catch the killer.
Most of my wife's books have been historical romance in the sub-sub genre of "Regency Romance" because they are set in the Regency period of England. It was popularized by Jane Austen in books like "Pride and Prejudice." Examples from my wife include her
Saint of Seven Dials series but she has
a good deal more.
They include one based on the true story of the sinking of S
.S. Central America with tons of gold in 1857 in a hurricane off the coast of Savannah. It's sort of like the movie Titanic with the hero and heroine fictional but almost every other character you meet on the ship being real historical people. It's also a fascinating true story of heroism on the high seas as about 500 men were killed but every woman and child on the ship were saved. If interested, check out
Ship of Dreams.
She also has a time travel romance where a modern woman trades places in time with her great, great, great, great grandmother in Columbia South Carolina. The book then follows both heroines equally as they fall in love with men their prior selves despised.
Bridge Over Time.
The books you guys have seen me posting most about here is her young adult science fiction romance series and if you want sex, well, there isn't any at all. Her
Starstruck series has won numerous awards as I type this she is right now slaving away on her computer revising Book 4 and the conclusion to the series (it will be called "Starfall"). Starstruck has a really fascinating premise to it that I think again shows there is more imagination to this stuff than a lot you guys think.