in reply to
Please explain WHY you voted --
It reminds me a discussion about the signal/noise ratio. Interesting things came out of it.
Based on this, for my part I don't always explain when I downvote beccause it would waste node only to say : offtopic, innapropriate language...
However I try to send /msg to the person explaining why, when I downvote.(I /msg to thanks for answer/comment too)
I ++ you beccause I really think that it's an interesting point :
If downvoting is an educating action, then you have to do it correctly and explain why you downvote someone.
But to be honest I think that we mustn't waste our votes downvoting whereas there are so many nodes to ++...