Yesterday I saw a couple of religious posts downvoted by a bot, somebody was taking the time to give them an upvote so they would be visible. So no, I don't think downvotes are of any use, while I have this feeling that there must be a creator somewhere I am definitely not a fan of religion or of reading what other people think about it, but I do think they have all the right to write about what they believe in, downvoting is just taking away their right to do so, and then the person who is upvoting could give that uvote to a more deserving post but doesn't because he thinks the post deserves to be seen even if he wouldn't have voted for it otherwise, have you thought about that?
As for the stats of the downvote, what was the activity level, more or less than the previous month? Yes, I know the percentage went slightly down, but if less people are engaging it means that probably most of the people who are posting are people who don't get downvoted.