What you've described is the case about any law or policy. And yet people debate them. Details of them. On the floor of congress, around the dinner table, on talk radio, on TV news, all the time. In public. And people don't whine and cry and complain about how mean voters are. Why should the corporate policymakers who write the TPP/TPIP get a special shield? Are they particularly sensitive and fragile as a class? Or are they writing laws that wouldn't survive a fraction of a second in public because they are corrupt and anti-citizen?

If you think people would get upset about trade policy, maybe you should look at issues that ARE debated in detail like abortion, gay marriage, gun control. People are murdered over these issues. Trade policy barely registers on the scale.