Is this a gender thing?

Rating: 4/10 (26 March 2012)

Took my girlfriend to see this movie, although neither of us has heard of the book or the film before. I saw a lot of merchandise in shops, and searched up the trailer, so I knew the main character is a tough and pretty girl and there is probably romance too. Sounds like the sort of thing she'd enjoy.
I thought this was a mostly boring movie and I just didn't understand a lot of the stuff having not read the book. What are they doing?! Why are they doing any of this?! Why does any of this matter?! It feels like a very cheap American imitation of "Battle Royale" made for cash.
However, my girlfriend liked it. She identified with the main character, laughed at the funny moments, jumped at the scary moments, and thought they did a good job with the costumes. She felt this was much better than BR and similar movies, because there is much less graphical violence, and a smaller caste of characters so they were characterized better.
So, is this a gender thing? Maybe I'm just not their target audience... ...