Downvoting for mere disagreement has been blessed by the top level; it's an HN 'thing'. It would be less of a problem if it didn't also fade your comment.
I rarely see well considered dissenting opinions down-voted into the gray. That is something that I typically only see when somebody is being uncivil, committing logical fallacies, mis-characterizing the arguments of others, or is factually incorrect yet self-sure.
