Ignoring Common Genre Themes (Is It Shooting Yourself in the Foot?)

I decided to be adventurous and buy a book of short stories by prominent YA contemporary spec fic authors. The stories were all about love, and I read it in the two weeks leading up to Valentine's Day. I noticed that all of the stories except one, while very different, had one common theme. Human main character (all girls, in this case) gets romantically involved with a non-human character. Then I look at the last two YA contemp fantasy novels I read. One was Twilight (I'm sure I don't have to explain). The other, Wicked Lovely, which was slightly different in that there were more than one POV, some human, some not (although the MC was still a human girl, at least at first), and the romance played out differently.

Looking at my own novels, I see a huge reversal. Non-human MC (usually a girl) falls in love with a human love interest (or someone who thinks they're human and has been living as a human ;-) ). Now with the other scenario, you have the option of the classic human-character-discovers-magical-world, which is nice for the author because they get to introduce the reader to the fantasy world without an infodump. The reader discovers it with the MC. But is there anything wrong with taking the POV of the "other"?

Of course, this brings me to two huge concerns. One, that maybe readers do have a problem connecting to the "other." Most of my non-human MCs have been very human-like, and I've never had a complaint about them (or the one who I thought would be hardest to connect to). But maybe it is a problem.

More importantly to the post is this. Is the reason that the novels and stories I'm seeing are like this because that's what the market is expecting now? In the wake of Twilight, is it expected that a paranormal romance or a fantasy with romantic elements has a human MC with a supernatural love interest? And does that mean it's harder to get anything else published?

I sure hope not.

Don't get me wrong, my enjoyment of each of those stories wasn't ruined by the fact that they had this common element, but wouldn't it be boring if every genre or subgenre was required to have the same basic set up?

And it's easy to say, "No, you want to be unique. It will get the agent's and editor's attention!" But when you see four stories in a book of five with that same thread, it makes you stop and wonder.

Anyway, within your own preferred genres (reading and writing), what elements do you see commonly, that maybe you've conformed to or perhaps completely ignored?