DDoS is the internet equivalent of a mob censoring public speech. Proxies like cloudflare are the equivalent of the police protecting the right to speak, no matter the view.
Remember that these principles, which date to the Enlightenment, work for all views and have benefited the civil rights, antiwar, suffragist, environment and other movements immeasurably.
But even if it was. You must get a permit just like in real life. Which a private entity doesn't have to grant you. Because you know... personal freedom.
The question is, should the Internet be a free and open public forum or not? Should we permit mobs to knock legal servers off the Internet?
That would seem to run counter to the idea of an open internet embodied in net neutrality, upon which certain laws have been developed and passed over the years. It would be a mistake to merely look at the current laws on the books without grasping the underlying general principles.
Not to mention access to Internet is considered a basic right in some countries.
So grand parent makes compelling case, just not in US laws.
Looks like some heavy reality bending for a questionable cause to me.