As I just mentioned, Cloudflare realizes that the status quo makes it hard to prove standing to sue them or to go after the attackers, and that's a large part of what allows them to get away with it. How is the FBI supposed to conduct an investigation here? They're not going to be able to get subpoenas for every single DDoS booter behind Cloudflare (one group has documented over 200 of them).
I recognize that it's impossible to eradicate the problem 100%, but by driving it underground, you can dramatically reduce the amount of it by making it harder for them to conduct their business. Cloudflare could do this in a day if they wanted to, instead they sit behind a "free speech" argument waiting for someone to force them to cut it out. Don't say I didn't warn you if the government comes in to change the liability laws to prevent this sort of behavior in the future. Nobody's going to defend DDoS spam packets from criminal botnets as "free speech" when they're preventing all speech from occurring.