User blog comment:Rappy 4187/Technical Update: November 30, 2015/@comment-25952539-20151130225448

"Templates will no longer be editable by anonymous editors, which also means they cannot change Template Types. From our review of editing behaviour, very, very few template edits are made by anonymous editors, and many are vandalism."

Well, it's a bittersweet change, but if the statistics say so...

The moral of the story is: get an account!