Wow, you've had some scary rabbits. I've never had one that was that bad, and none that were mean to humans. I think part of the problem is that the general consensus is that rabbits are like the Easter bunny. Cuddly and sweet. They are prey animals and therefore have to be able to attempt to defend themselves. And they see humans most of the time as predators. I have and have had lovely rabbits, but I respect their limitations and their fears. Certainly there are very friendly rabbits, I've seen them both in the shelters that I have volunteered in and at friends homes. That being said, I think it is probably, again in my opinion, not wise to put them in with the ducklings. If they were to need to defend themselves, and did hurt the ducklings, then they would be blamed for being the aggressor, And I don't think that's fair. Animals are animals. So it is up to us to keep all species safe. And to provide them with the best home we possibly can.
Yeah they were not very nice. Maybe just bad luck? I know people who had wonderful rabbits so I know they can be great pets.