She's doing what teenagers are supposed to do. We're supposed to do stupid things as well as try new things and see where we fit in with them. It's not that everything she's done is appropriate nor is it excusable but at the same time it's understandable.
Could Miley have expressed herself in a subtler manner, sans twerking teddy bears? Perhaps. But if she wants to use that extreme form of expression to shock people and create publicity, then shouldn't she be able to?