Erm, no, I don't think so. If you use the web and want to do something you would always enter mickey@mouse.com into the e-mail fields if required and imagine we would have the people to say: I downvoted because of missing information/ wrong information/not getting the point/I don't like the person posted. Would you feel better or even more hurt when the downvoters now will take their real chance to hurt you and to downvote you and to tell you that they don't like you and you'll never get them? And if you ommit the latter option to state the reason for downvoting you 'll get political correct statistics that are worthless in the real world.
0.02
Have a nice day
All decision is left to your taste