Why is it so slow to add new features and technologies then? It took them, what, like 3 years? To add TRIM support for SSDs? Their first attempt at ASLR was woeful and badly broken and even that was a year after Vista got it.
They're not slow to add features. Some may arrive after a competitor, but every release of OS X sees low-level feature additions and updates. They're documented by Siracusa's mega-reviews as well as the OS X release notes. Nearly Apple's entire product line has been dependent on the flexibility of that foundation, from the PowerPC Macs to the Intel transition to the ARM squeeze, not to mention the recent ARM64 port. So, I don't understand why you think Apple can't or won't work on the foundation or why you believe it's a monolithic relic written in the 1970s, unless you're just referencing some vague bias against Unix in general.
You're really digging in on this aren't you? I wrote very clearly that it was only a suspicion clearly in an attempt to explain why they are so much slower at improving their OS kernel than Microsoft is. So any time somebody makes a suspicion you'll arrive and interpret it as though it was a statement of fact? Noted.
Meanwhile, you make woolly justifications of their slowness by making contradictions like this: "They're not slow to add features. Some may arrive after a competitor" Comments like these are not helpful and do not add anything to the conversation.
They're slow. The reasons why this is the case is still not entirely clear. But even OSX fans get frustrated sometimes at how slow they are to add features that other operating systems got years before. The most vocal recent one I can think of was probably the TRIM support for SSDs.