Selena Gomez and Justin Bieber arrive at the 2011 American Music Awards at Nokia Theatre L.A. Live on November 20, 2011 in Los Angeles, California. (Photo by Steve Granitz/WireImage) Pop star Selena Gomez has applauded her ex-boyfriend Justin Bieber for making a successful career comeback. The two singers dated on and off for three years, but split for good in 2013. Justin endured a number of personal problems while they were together and after the break-up, including several brushes with the law. Selena admits critics thought she was “stupid” for dating the troubled star, but insists his pop revival has shown the world the Bieber she fell for. “While people