Apple shifts from Objective C to Swift

I quite agree with your suggestion that this is, potentially, more about NIH syndrome rather than a necessary change... which does not preclude that it is going to turn out to be a useful evolution in coding...

My hypothesis for why every big company might make such moves at some stage -- if they can -- is the temptation of control. If you support standards, common tools, etc., then people might build things that you haven't anticipated in ways that you might not be able to mediate and so on. I think the business case for control and lock-in seems obvious to many, but I also think people try to create "the foundation" for all other activities based on their personal outlook. I have seen spouses, bosses, children, etc. try and exert "their way of doing things" on everyone around them simply because "their way makes the most sense". To move in the other direction, i.e., to facilitate many different people's outlook or activities pseudo-equally, a given person or business must be able to value the cognitive dissonance that can arise when other people want to arrange or do things on their own terms... just a thought (and probably not well formed).