The core problem is that conversations aren't one way highways made of high-value comments. Sometimes interesting things may come out of silly ones. Or maybe n

The core problem is that conversations aren't one way highways made of high-value comments. Sometimes interesting things may come out of silly ones. Or maybe not. If we assume a conversation is also (not only) as a creative process, then mistakes and silliness are simply part of the process to get to something interesting. Now, don't get me wrong, I'm not advocating the "far west" attitude; I just think that the up/down voting works enough for the purpose. Introducing an extra layer is going to push people to behave in a certain way (that somebody define, in an extreme way, groupthinking), which may make things more interesting in a certain way, but far less interesting in another. There was a certain experiment on a certain site where they switched to Facebook comments, and they found that trolling comments were drastically reduced, but the posts started to look to nice and compliant. Also, very important, the new system replaces a democracy with (more or less) an aristocracy, and I some doubts about this.