The intent of that comment was to demonstrate that having CASL in place really hasn't had an impact on the volume of spam coming to your inbox. The ISPs are managing that for you. There's a technical solution to dealing with most of the spam that comes through right now, and companies like Microsoft and Google and others that are managing your email accounts for you are filtering out most of the spam that comes through the system. They're the ones spending the money to make that happen.
On October 5th, 2017. See this statement in context.