Right now when custom public views are enabled on workbooks the only person with the ability to remove it is the creator of that view, not the publisher or a server admin. I realize custom views don't give additional permissions but server administrators and the owners of the workbook should have the ability to remove the custom views.
This can be useful for a few reasons:
Your workbook has many users, and many abandoned custom views - Over time views can add up, if many users make them public you have to track down every one and convince them to remove it
A view is out of date - changes to the data or format make the view irrelevant
A view is named poorly - "Tableau Server admins are powerless" or "confidential title here!"