I'm sorry for assuming you were bothered by it. I actually don't know you so well. Most of your posts do see great though and I know quality and dedication when I see it.
I know many people who are bothered by this guy aren't just profit-seekers who see the downvotes purely as a cut into their earnings. Most of the people complaining probably are genuinely hurt and insulted. However, I still think people should take downvoting a lot less personal.
I just choose to completely ignore it and consider it a cost of trying to seek rewards from posting.
Maybe standing up to him will work and I hope it does. But I still don't think of this as bullying. I think there are other deeper issues involved.
A consensus has developed regarding what is the right and what is the wrong behaviour on Steem. His behaviour is clearly wrong according to that consensus.
Without a centralized authority, maintaining balance will never be easy. There are some deep rifts on Steem. Some people want full out vote-buying to come back. Others don't like this grey area.
If I had to guess. He is the clown who won't find a new target (his net is already so wide). He wants free downvotes gone and perhaps vote-buying to come back (you mentioned he owned a bot).
My experience with bully behaviour is that standing up to it doesn't always stop the bully but it does encourage others to also stand firm rather than feeling they are alone and need to give in.