The law says (in the interpretation of the judge, based on the facts available) that backers are entitled to refunds. Since the company refused to provide those refunds willingly, and had to be forced to do so by the legal system, it doesn't seem unreasonable for them to bear the associated costs.

Plus, it's a deterrent. If losing a lawsuit meant you only had to pay for the damages you were originally found to owe, then everyone would challenge every claim even if they had a near-0% chance of winning, and the court system would be totally overwhelmed.