I agree, in principle.
in reply to Explanation with ++ and --
in thread Reputations
Of course, the other side to consider: most of this site
is geared toward encouraging us to post. While I really
like your idea of a separate (and private) feedback system,
the goal of Perl Monks is to generate traffic for the banner
ads. Lots of posts to read means more excitement about the
site, which means more traffic, which means more revenue.
Since negative votes should be rare (and justified), perhaps
a "middle ground" would be to require an explanation for
negative votes, but allow normal posts for praise/positive
votes. Explanations could be very short, and would be
delivered only to the author.