No, it's demographics. The majority of the voters for the MTV movie awards are tween/young teen girls. Harry Potter's not going to win anything, and -- despite me being a huge fan of HP -- that doesn't really bother me at all. MTV is crap.
Oh, just a fun fact for the day. I had a class last semester with a girl who was on MTV's "16 and Pregnant" (classy), and a camera crew totally came to class one day. It was awkward. So there...