I think that the signal/noise ratio would get higher.
We could adopt a convention that when you vote, you post a short comment to explain your rationale.
???
Why would that be bad?
Because then the site would be like Reddit - interesting content that is impossible to find in the vast froothing sea of Ron Paul submissions, funny pictures and conspiracy theories.
:-)
Then I think you meant that the signal/noise ratio would become lower.
Oooops....
You're right. Sorry about that.
This subthread is an example of the ratio getting higher.