I understand what you mean about never having a mean rabbit until you got these rabbits. The same thing happened to me and I was suprised by it.
I have raised lionheads for years and never had a mean one.
My daughter brought her neighbor's rabbit here because they didn't want it anymore. Now I know why. She is mean and aggressive.
When I go to feed or water her she comes at me with her ears back and strikes at me with her front paws and tries to bite.
I have a lot of patience and enjoy working with troubled animals. I read up on rabbit aggression and have been working with her, with no luck so far. She likes other rabbits, dogs, cats...everything but people.
I put a long sleeved sweatshirt and gloves on to protect myself and put her in an outdoor run, in case it is cage aggression. She will take treats from my hands and then grunt and smack me with her front feet. She isn't afraid to come up to me. But everytime she does, it's to attack me.
So, I guess mean does do exist. I would have never believed just how mean they could be until I saw it for myself. She has been here for a couple of months now with no change in behavior.
Good luck with yours. I just wanted you to know that I can relate to what you are dealing with.