The problem for Apple is that doing that would then hold them back; they would be required to not break other people's code with new releases, and I feel they w

The problem for Apple is that doing that would then hold them back; they would be required to not break other people's code with new releases, and I feel they would like to be able to completely reqrite large parts of Xcode as often as they like without worrying about outcry when they break someone else's code.