Joanna Bourne compares genre covers with romance covers and offers her angry opinion as a historical romance writer:

What does this say to the world about Historical Romance?
It says, “One Romance book is like another.”  It says, “No story inside this book, Ma’m. Just pick one at random.”
This is so much lack of respect.
I hate this.

Check out her visual comparisons: http://jobourne.blogspot.com.au/2012/05/this-is-what-i-hate-about-romance.html