Most of my downvotes are not solely because I disagree with a particular point of view, but because the opinion presented seems to have been formed because the

Most of my downvotes are not solely because I disagree with a particular point of view, but because the opinion presented seems to have been formed because the poster is missing a fundamental fact that is crucial to the opposite point of view. I can't tell if he is ignorant of this fact and would change his view if he knew, or if he holds his opinion despite it. Expressing a contrary opinion requires suitable acknowledgement and refutation of the arguments going in the other direction if it is to have any merit. If such a fact is acknowledged and refuted, then I am happy to upvote.