Because it's different styles of husbandry.
Personally, my meat breeders were in 36x36 cages for the larger rabbits and 24x24 cages for smaller rabbits. They weren't pets, they were livestock and lived in a barn.
My friends each dedicate a portion of a room in their homes to their individual...
Depends on who you ask and what you're planning to do with the rabbit. Pet keepers will probably have issues with the floor at least, likely the size too. Most that raise them for meat keep them in smaller cages for grow outs with wire floors, with a solid spot for them to rest their feet on