All three artists have wonderful voices, great musicality and, for the most part, produce some good songs. (Not necessarily all my taste in music, but I'll give them their due nonetheless. I din't much like Michael Jackson's music either.)
Having said that, I must immediately say that 'Wrecking Ball', as good a song as it may be, has been truly spoilt for me. Every time I hear it I can't help myself from associating the song with a video of a naked waif riding a wrecking ball and simulating fellatio with a sledge-hammer. It's hard to acknowledge Miley Cyrus' powerful voice and musical ability in the context of her overt sexploitation of her audience. Her twerk-fest at the MTV VMA awards was likewise so far from appropriate that she lost the song on most everyone who had the misfortune to have to watch her antics. In her misguided attempts to push up ratings and shed the good girl image, she's managed to confuse her audience about whether she's a good artist or just out to prove that she can simulate sex with the best of them.
Rihanna's thrusting around in 'Pour It Up' takes tasteless to a new level. Her lip synching at the recent concert in Johannesburg was simply plain fraud on the paying public. Justin Bieber's recent run of discourtesy to his fans and showing a middle finger to the world might appeal to some, but I know of plenty of ex-fans on account of his lack of discernment and jerk behaviour.
And yet artists like Michael Buble, Katie Melua and Barbara Streisand have apparently never felt the need to twerk, jerk or thrust in order to boost their album sales. They just keep on showing up as their authentic, lovable selves and their fans appreciate and adore them for what they are: incredible musicians, thoroughly decent and relatively uncomplicated human beings.
The drive to prove oneself through dramatic, undiscerning and inauthentic behavior might be intended to impress, but the cynical part of me suspects that the true purpose might be to distract the fan with sensational stuff lest the artist be found out to be a bit of a fraud, perhaps not as good as she or he wants fans to think he/she is. Miley's thought pattern might be something like this: "I got away with it as Hannah Montana and I've got away with it so far. But I think I'm not really that great - a bit of a fraud - so let me hedge my popularity base with something outrageous which will make them think that I'm not only a good singer, but quite cool and risqué also."
The tragedy is that the artist, by behaving in a way which she thinks will guarantee her future audiences and pump up her album sales in fact loses a big chunk of fan base: she brings about the thing she most fears, rather than honoring herself for the incredible musical gifts she has.
It comes down to how she esteems herself: if it is by thinking that a wrecking ball-type scene will cause people to love her more, she might as well change her career to pole dancing. That way she can at least guarantee the type of fan who follows her. Disappointingly, whilst her reality might be that people will love her more that way, she has forgotten to credit her audience with the gift of discernment.
If you want to be known as a singer, or performer, or indeed anything, authenticity is the way to go. That way you're less likely to lose yourself and your message to the vagaries of your own insecurity.