There's often a need to check/inspect an item you have listed. For example, if a customer reports a fault then you will want to inspect the exact item that was bought. At times you may also just need reassurance that you have listed the final correct version. We all get distracted at times, and may just want to check.
Since there is no way to check your item after listing it you need to go to the extremes of deleting your listing and creating a new one. This means you lose ratings and all purchase history.
The ability to update an item is related to this, and will be another request.