He's an easy target.
But all human beings go through adolescence.
I imagine it's even harder to go through adolescence in the glare of the world media, being one of the most watched, discussed and adored people in the world. That's an extreme amount of pressure, especially for a teenage boy with a lot of money and a lot of female attention.
All people make mistakes. Justin Bieber has simply had the unfortunate position of having to make all of his mistakes, to learn all of his life lessons, in view of the world press.
I saw a few interviews of him recently and he struck me as a rather insecure person, behind the bravado that has come with being signed up to Usher and hanging around with people like Kanye West and Jay Z, who will have had a formative impact on these quite important years from adolescence to adulthood.
At 21 it's normal and reasonable to not know who you are completely as a person, and it strikes me that Justin Bieber's had so many expectations and lifestyles thrust on him that he's hardly had the space to understand himself yet.
People could give him a break.
And his music is decent enough -- at least he writes his own music. 'Sorry' and 'What Do You Mean' are good songs imho, catchy as well as having lyrics that show he clearly does have a brain; his songs literally tell the story of the normal process he's going through, that all young people go through, which he's simply having to experience while being constantly judged on everything he does.