Too many participants and too much scrutiny can lead to paralysis. I thought this was one f the major weaknesses of the Occupy Wall Street movement; for some reason they decided their general assemblies should run without any procedure for terminating discussion, and that no resolution could be passed without 90% agreement. Predictably they never managed to settle on a list of demands before the momentum evaporated.
I appreciate that you may find my realpolitik approach somewhat lizard-like.
Why? Because IP and DRM are ultimately a small part of the trade puzzle, dwarfed by issues like agricultural trade barriers (eg Japan's 777.7% tariff on imported rice, in a country of ~120m, most of whom eat rice daily, which amounts to billions a year in deadweight loss on a single commodity - see http://www.nytimes.com/2010/11/12/business/global/12yen.html... for background).
Personally I think the secrecy has a lot to do with preventing interference by China, which is conspicuously not part of the treaty negotiations. You may recall the administration is trying to effect a 'strategic pivot' towards Asia to counter China's expanding foreign policy influence. Thanks to the oil & natural gas boom, the US is well on the road to energy independence and thus the Middle East is no longer the nation's major strategic focus.