Genre Blenders.

Or why I find myself scrolling past anything that says "Harem" on the cover. It all started with a series called "Anita Blake." It went from a popcorn entertainment level mystery urban fantasy w/ some romance elements to IKEA manual "Please Insert Anita over X body part here" plotlines paranormal Pornmance. It's not even actually erotic. Its a train wreak.

When that character went to Florida in some of the later books, based on the blurb, I kept hoping some Super Gator would have eaten everyone. But what caused everything to sour so much? What drove away the original fan base that supported the first few books? Lots of things.

• There's no actual emotion to it. Insert Y. Begin. Please remove M. It's even more flat and comical then that Mass Effect joke of "We'll bang ok?!"  
• https://tvtropes.org/pmwiki/pmwiki.php/Main/DearNegativeReader
• http://fantasy-faction.com/2011/anita-blake
• If you want to change what you are writing that drastically, create a new series, or end the one you are doing then go full hog on a different set of characters. It has the hallmark of "Lets subvert expectations." But we all know how that goes. 
• My personal tastes: Just fade to black in most cases. If I wanted a "Complete and Total" bodice ripper I wouldn't be reading sci fi or fantasy. I'd be going for the Harlequin Romances.

Example: Of tastefully done romance. You write characters like this and Ill be a fan for life.

• Because it showcases the characters have genuine chemistry
• Caring
• Empathy
• Not just physical

Once you put something out there, the reader and writer end up as a team of sorts, sure write what you want but do your best to remain true to the books you are writing. If it started off as a Urban Fantasy/Detective type setup, don't change it up midway through the series to Paranormal Erotica. Just my 2 cents that is.

I suppose a good contrast to this would be:

Plus, depending on what you are looking for, she does this very well with other types of couples too.

It's exactly what it says on the tin. She uses the tropes very well. You can have a book with many different genre elements that develop over time. You just have to put it in gradually. Not pull the genre rug from out from under people.

So yes, have your space opera mega romance or military sci fi detective mystery. Just be up front about what your book will contain. Ill be doing that for my series blurb too. Once its finished. 

Guess it mostly comes down to personal tastes. I just wish books would list themselves properly in genre categories.