"Throughout our history" means throughout our history without computers, billboards, the internet, social networks, cell phones, cars, or a global economy. Our history shows that democracy is a shitty form of government, yet we have one.
I think people really underestimate the power of huge companies and, I'll say it again, advertising. Companies can advertise without violating regulations and still fuck with consumers. Society wasn't and isn't really ready for it.
You talk about tests for voting, but they're unconstitutional. They used to have them in the South to prevent blacks and poor whites from voting. Plus, anyone can pass a basic knowledge and competency exam. Tests for voting really aren't practical. Democracy is a very very flawed system. It's not natural for people to be equal under the law and have an equal vote. For the average person it sure beats communism or monarchy, but if we want democracy these are the kind of shitstorms/issues/debates/fuck ups we're going to have to deal with.
You have some sound reasoning, but I think all of us are too focused on the small issue and not the functioning of society as a whole.