You probably don't because net neutrality isn't an automatic win for everyone. Some companies clearly benefit from the repeal. They do have incentive to invest in their networks when they can monetize it every which way, it's now a feature they can charge for...

Except maybe for a PR tidal wave so huge that anyone who opposes net neutrality is driven out of business, I don't see how you convince companies to go against their own interests.

You don't - you can only change the rules of the game so their interests are set in line with public opinion, or environmental standards, or safety practices, or whatever else.

^^ Right answer. Board members will be upset if companies don't do every thing they can to increase profits, including "persuading" members of Congress and swaying public opinion. Our job, as "civilians," is to set the rules of the game the way we want them. The companies won't- unless there is accidental alignment between the company's goals and ours (in this case, small companies may align for example).