The Tor browser doesn't block ads. Just javascript and flash. His point is the internet is becoming increasingly hostile to privacy. It's already extremely difficult if not impossible to create anonymous accounts with tools like Tor. Which discourages things like whistle blowing, or people from areas with oppressive governments.
The problem is that every website does the same thing, and now it's impossible to use the internet anonymously. But actual spammers can spend a few bucks on IP rotating services. IP discrimination causes far more harm than good.
Actually I don't think Tor disables javascript by default anymore, but even when I do disable it I still see ads.
