Admins need to be able to see and edit all reports.
All too often, someone may leave or not available and a report needs to be updated; however, because the original owner restricted it to be view only, we end up creating another report in order to make the update.
This results in increasing the number of reports; causes confusion as to which one to use and then results in inconsistencies if that original report was being part of a dashboard or presentation and doesn't incorporate the change.