Why would we do that? Who's asking for such a feature?
It just seems reasonable that we be able to turn off a feature which has such wide-ranging impacts. This should be easy to implement given the architecture but it's getting pushed down my list by requests from Rook that are turning up now we're actually trying to integrate it into their way of life.
This is (to the best of my knowledge) and OCS requested feature - they are not going to go back. Deferring to 5.1, at least.