Revert (inherently unsafe) creation of non-existent instances option/feature

  There's a great saying in the usability world: "You can't
  document your way out of a usability problem". What it means
  is that if all the affordances of your application push users
  towards a particular logical conclusion, having a caveat in
  your documentation isn't going to help, because people aren't
  even going to think to ask the question.

  It doesn't matter if you originally had a good reason for the
  behaviour, you've ended up in a place where your behaviour is
  confusing and inconsistent, because there is one piece of
  behaviour that is out of line with an otherwise consistent
  mental model.

      -- Nick Coghlan

This reverts commit dfe2d0f0b28ed012274570d8a419ca653ff50a35.