can one fish better by muddying the waters? isn't that what Howard Zinn is trying to say here?

I had to read your question several times before understanding it and am still not entirely sure I have your meaning correct. I read the article supplied in your link however and found it interesting. Howard Zinn appears to be saying that by spending so much time and effort on finding out the truth behind 9-11 we are doing a disservice to ourselves because we aren't allowing open and honest discussion on a large scale of what leads certain groups of people to hate the US with such venom and desire to destroy us. I don't believe the official government version of what happened on 9-11 and never will, and the timing was so convenient to Bush regarding the war on terror and passing the Patriot Act with no oversight and turning him from a laughingstock into a President that people actually supported and approved of, that I will always wonder what the real story behind it was, but realize that I will never know the real story of what happened. The US government lies, I don't trust them to tell the truth and some of the 9-11 conspiracy theorists come off as certifiably insane. I for a time was caught up in that and believed it, but have since revised my thoughts on the matter.

We are so busy focused on discovering the truth of what happened that day that we are largely ignoring the reason why it happened. We ignore the things our government does abroad to foreign nation that inspires such hate in some people. We continue to ignore the things are government is doing abroad to foreign nations in our name, bringing more fury to the US and leaving us open to an other attack. The conspiracy theorists benefit the US government also by attributing the ability to pull of such an attack of enormous proportion without a single person revealing it along the way, they perpetuate the illusion that the US government really can and would do anything so watch it, don't cross them.

Professor Zinn is trying to refocus the audience, from ethereal speculative discussion, onto the US foreign policy which has resulted in people ragingly angry across the planet about the US foreign policy.

Check out "The Shock Doctrine". US foreign policy falls into the script of providing resources for speculators, at the expense of weaker or indigenous people.

edit; of course the powerful cabal members will devise and use every contrivance to continue their own agenda, including espionage. These are the political leaders staff, the illuminati and bankers, people whose names are unknown but whose actions affect millions. Your question about muddied waters reminds me how much I value truth in my daily walk. Suppose only facts not conjecture are spoken in the world. We would own our emotions, instead of their being bought and sold for corporate and political gain, traded on the open market for leverage in the boardroom..

1) Little Dumbo 0bamer says we must donate money to the Rich!!!