The Writer's Guide to E-Publishing (a site I absolutely recommend to anyone who is pursuing a writing career), discussed the eras that traditional publishing won't touch in the romance genre. Eras such as the American Revolution, the Civil War, and both World Wars are absolutely verboten, according to agents, editors, and publishers. However, the Viking Era, Middle Ages, Regency Period (and that would include its predecessor, the Georgian Period), and the contemporary period (BUT not the period from the mid 1940s to the mid 1980s) are perfectly acceptable. Well, that explains why there are a million duke, prince, king, etc. romances out there. They think these are what people want.
Don't get me wrong. I like a good randy count or duke story, but how many of these can one read? And the Vikings? These are the same people who pillaged monasteries, leading to nuns cutting their faces to make themselves unattractive enough to avoid rape. Incidentally, it didn't work and the Viking marauders would rape them regardless and then burn down the buildings they were in, killing them all. This is where the idea of "cutting off your nose to spite your face" came from.
And the Middle Ages? I'm a huge fan of this time period, but how many of these stories can readers actually want? The reality is that readers would probably like romances set in other eras, particularly in the Civil War period. Have these editors and publishers ever heard of Gone With The Wind?
I would add that there seem to be a list of acceptable places that traditional publishing believes hot men exist. From what I can gather, the traditional big boys believe that sexy male heroes reside in these places:
The Scottish Highlands
Anywhere in England, as long as it's during the appropriate time periods (see above)
On the coasts of the United States between the late 1980s and now (but less toward the Southeast)
Deserts in the Middle East (sheiks are super popular, it seems)
I'm sure I'm missing some, but I sense a deliberate exclusion of the Southern United States (perhaps that has something to do with their Civil War exclusion).
Beyond time and place restrictions, traditional publishing seems to think that readers must have a Happily Ever After. The HEA is paramount. I, for one, think this is an exaggerated requirement and sense that readers would be ok with a little variety. Yes, they read to escape, but knowing the ending is the same all the time can't be the most important thing to the story.
It seems that the time for change has come. Even the smaller e-publishers are going to have to accept that indie publishing is changing the rules. The ability to offer your ideas to readers without going through the gatekeepers is a revolutionary one, and I admit, one that I didn't consider at first. But now that I am into this a bit more, indie is looking more and more attractive.
The reality is that today there are so many more people feeling brave enough to tell their stories, and indie publishing offers them that choice. So the writer who wants to tell a story about the Civil War that involves romance but isn't truly a romance can offer this to the world and let readers decide if they want to read it or not. The only gatekeepers in that are the readers themselves.
That must scare the hell out of the traditional publishers.