In reality, even if I get to joke about my concepts of Watership Down in the Himalayas or Watership Down with Pikas. Also you know how it really bothers me the whole idea of trading rabbits with hares lol.
Because that changes the story completely and is just another example of people not being able to let go of the idea that the only relevant element of WD has to be violence and darkness and death. Hares are solitary by nature, they don't fight each other unless it's for mates. Basically the whole plot of finding a new home and community and leadership and the downtrodden is not going to happen that way.
You would have to be creating an original story instead rather than adapting.
Because the story is about rabbits, you're not going to trade the lion king for tigers just because they seem more "awesome" to you. Or White Fang for a coyote because of the dynamics. I know that as such there are adaptations that can turn a story into something completely different while still keeping the idea of course, but the thing is that they usually also try to be something new as a product rather than an adaptation itself.
And well the stigma that rabbits are cute innocent creatures and hares weird Lovecraft cryptids. It's changing unknown aspects of their nature just on the basis of how "disturbing" their appearance is.
For starters the terrible stigma Watership Down has of being just a "scary" story has a lot to do with it, no it's not. It's a story full of layers and it bothers me a little to know that because of scenes in the film they have to believe it is.
Plus the rabbits themselves have another stigma. People just can't help but see them as "cuddly critters". When they are not, rabbits are also WILD ANIMALS, they have to deal with a lot of crap every day, rabbits also fight, bleed and bite each other to death. Any rabbit owner knows how terribly chaotic they can be and wild rabbits are aggressive as shit with each other.
Stories like Watership Down HELP remove that stigma, even with certain outdated or unknown topics at the time Richard Adams managed to make his slightly to anthropomorphic rabbits feel like the non-human animals they are, he gave them culture, language, myths and mild intelligence but adapted in a way that sounds believable to anyone who knows the basics about rabbits, even the story itself is filled with thousands of facts about these animals that allow you to learn about them.
Watership Down doesn't censor their reality, and not just because they kill each other or some stupid thing they always say. It doesn't censor the rabbits as the animals they are, they eat their waste, they have in mind the idea of reproducing almost as a law, they are not immediate friends of their animal companions and they even have a hard time communicating with them.
Watership Down is about rabbits because it shows their reality, their anguish and daily struggles, events that although fictional and sometimes fantastic are not far from the possibilities of what a rabbit can do. And it also works with rabbits because it has the whole element of community, family, peer bonding, leadership and knowing one's value and what one is good at.
A lot of that is lost if you simply change them for another animal simply because you think it covers a false "aesthetic" better and it's just the same story but made up by changing its nature.
It also bothers me because people just don't understand that they are different but related animals.