It was not the non-violent protests but the broken windows, tear gas and rubber bullets that received media attention. The mass media, while depicting the violence in a negative light, also reinforces it by paying more attention to it than non-violence.
Violence is more dramatic than non-violence.
It attracts television viewers and sells commercials. I feel little empathy with the broken windows of Starbucks, the Gap, and Banana Republic or the companies which own them. I am sure they will pass on the price to the consumer in the unlikely event that their insurance doesn't cover the damage. And what they lost in business, the people who fix the glass will gain. To borrow an argument from Piven and Cloward, what causes change is disruption.