The process of institutional change is never easy or painless. You can't make an omelet without breaking eggs. They always squawk and complain, and often ask government to bail them out. Most economists take it for granted that organizational change is progressive, that markets evolve from less efficient to more efficient arrangements. From this perspective, the answer is simple.
Technology is power.
Networks are seen as efficient. Others argue that autoglass networks serve as a means for exploiting consumers and shops through insurers' control over claims. Taking profits at the expense of consumers or rivals is anticompetitive, and against antitrust law. Here, insurers are seizing control, by steering claimants to cheaper repairs while exploiting their trust. But systems can be profitable for some and not be efficient for all.