Roles and responsibility changes often, people come and go, and especiallly in this field. When an analyst leave the organization, if she deletes her account, all the segments and reports associate to her are forever gone, yes, she can transfer those to someone else, but to who? Until a replacement is there, no one really cares, or has the expertise to manage those segments and report.
i wish there is a concept of Segment Repository, all admins can put segments in this repository, but those segments are not tight to any user account. They are not public, because not everyone needs to havce access to them. See it as a centralized repository for segments, I can see many benefits to having such thing, please vote for it.