Good question. I do believe that laws matter. I'm just skeptical that they'll always prevent abuse by the leadership. Look how the Patriot Act invalidated many basic rights, rights that were enforced by laws. Now they want to reauthorize it. Can you blame me for being skeptical?
I'd rather give the government just enough power, rather than a large amount of power "just in case". In this specific case, I'd rather the president not have such a power, lest he decides to use it in an absurd way in the future. (e.g. America gets attacked again, like 9/11, president pushes button.) Especially since these laws are being proposed and voted on by people who think that shutting down the internet is the way to protect yourself from "cyber attacks", whatever that may mean. They are obviously unqualified to make such a decision, as is the president unqualified to decide when the button must be hit.