Last modified: 2008-04-14 19:57:46 UTC
Third-party users may want people to be able to (easily) delete the Main Page just like they may want people to be able to delete more than 5000 revisions. Please make deleting the Main Page a permission like bigdelete which is simply not assigned for WMF wikis.
There's no restriction against deleting the main page in MediaWiki.
There's a custom extension installed on English Wikipedia for this.