No argument. But I see this as vindication.

ISPs are now so sensitive to not allowing spammers that the RBLs can't make money from it anymore.

They come across as pretty scummy: "Yea, we put your whole VPS provider in our blocklist. It's their fault for having one spammer customer: Blame them! By the way there's nothing you can do about it--except of course pay us to be whitelisted..."