There are some people who read into this story and try to place blame on Bathsheba. Their reasoning is she was trying to seduce the king or she should have been more careful. This isn't supported by the biblical text, but it comes up whenever David and Bathsheba is mentioned. Somebody will ask, 'Well, what was she doing bathing for everyone to see??'
The fact of it, though, is God doesn't blame Bathsheba for anything at all. The punishment is carried out solely because of David. Why do we feel the need to read into this? Why do we want to add to the story? I think it's partially because David is commended as a man after God's own heart, and no one wants a man of God to have so much sin in his life.
Here's another story on the opposite end of the spectrum. In the beginning of the book of Esther, the Persian king Xerxes throws a banquet. When he tells his wife Vashti to come join him and his guests and show off her beauty and her royal crown, she refuses. They throw her out of the palace because she had the nerve to disobey the king.
Some sources try to say that King Xerxes wants the queen to come parade around naked. Others say everyone in the banquet would be blind drunk (and it does say King Xerxes was "high in spirits") so it wouldn't be a good place for Vashti. They claim that it was common sense not to go. This isn't supported in the biblical text or in the historical studies of ancient Persian culture.
Again, why are we adding to the story? I know the Bible leaves a lot of details out, many of which deal with the motivations of these people. But I don't think we should be adding our own take on things. I think when we do that, we make our own meaning of the story. With Bathsheba and David, we can say the moral of the story is, 'Don't seduce men with your body' and with Vashti and King Xerxes, 'Stick up for yourself.' Although these messages are found elsewhere in the Bible, it's not the message of these stories. The point of the story of David and Bathsheba is to show God's grace (David sinned and yet God gave him a successor to the throne through this union), and the point of Vashti's story is to set the stage for Esther to become queen and to show what Esther was going to face.
When we throw our own interpretation into it that isn't backed up by the text or by historical interpretation, we step away from the original meaning. I think it's okay to theorize - people always will - but we should never treat our theories as fact.