Yes, I dont believe that too many of them are there just for the experience, or to find themselves. I think when you go into something like this, you go in to win. I still think being yourself is the best plan. If you are a nice person outside the house, you will probably be the same inside the house. If you are a whining arsehole outside the house, I dont think the Big Brother house is going to change you, for the better.
I think a lot of them probably learn some good life experience, by having to be part of a group in a share house and mix with people they probably wouldnt give a second look on the outside. But I do think that they all go in with a plan, to win. With as much as a million dollars up for grabs in the past, if you dont have a plan, you're an idiot. As I said, I still think the best plan is to be yourself, some people will like you, some will never like you, just like in real life.