I don't mean to imply this was the OP's fault, nor that he isn't due compensation, but hotel security is a SHARED responsibility. The OP could have taken additional steps to protect himself. Whether those would have been good enough to prevent what happened, well, there's no way to know. The hotel can have all the security in the world, but if I hold the door open at night to let someone in, I may have just thwarted the hotel's efforts.

Let this serve as a reminder to each of us the importance of making sure the door is closed, the latch is locked and the bar is closed. While the perp may have still gotten in the room, there would have likely been more noise.