I'm pretty certain that Charli XCX could write something stratospheric for Justin Bieber, but why would you want to? If you had a song that Justin Bieber could do well, why not give it to someone who could do it better?
But Charli seems to (over)rate Bieber:
"I like Justin Bieber as a pop star," Charli XCX told Billboard at the MGM Grand Garden Arena. "I think he's really, really great. I really love the song 'Baby.' I think it's awesome."Really?
It's like that Delia Smith gave the okay to instant mashed potato, isn't it?