I think we have been stuck with this for so long we have forgotten that any other way is possible. Scrum is just a complicated way to divide labor. No one else at a software company needs a formal process to partition their work. They just sit down, talk and then go do the work. They come up with a light weight way -- a informal process -- to get stuff down. They would never even think to ask themselves, "I wonder what formal process we can follow to assign work?" They just do it.