I think is is more due to being in Hollywood and therefore being exposed to people with little to no moral fiber.
Billy Ray is regetting his decision to let her do that show. As always it comes down to the parents. If you willingly let your kids spend long days with people you know to be pedophiles, deviants, drug-users and other unsavory characters, you shouldn't be surprised when they emulate those behaviors. In the article he talks about being bullied by Miley's "handlers" -- What? How did you loose control of your own daughter to strangers?
As leftist as the folks at Disney Channel are (I hate the Michelle Obama good eating crap) , they have a brand to protect. I can't imagine they are terribly excited over gaining a reputation for destroying their child stars. My kids watch a lot of Disney, and while we have banned some shows ( mostly for stupidity) , most of the shows are pretty darn benign. Or as least I find them so compared to Nickalodeon or some of the other alternatvies out there. When the shows get off track, I turn it into a teaching moment. Its better kids see bad behavior and then be told its bad, rather than have them figure it out the hard way. I do the same with movies ( Now kids, I don't want to hear that word from you unless there really is a giant dinosuar chasing you. If there is, then its completely appropriate to say that. )
With that said, I fully expect Selena Gomez to start pulling Miley-type antics any day now. Its sad, she was such a cute kid when she was on Barney
All I can tell my kids is that these people are actors. They lie for a living. They are not people to be admired or emulated in their daily lives.