It depends on what we're talking about. I would expect UI design elements to merge where the capabilities of devices are converging. That's not happening from the desktop since Apple is against desktop touch input; if anything the mobile side should be moving closer to desktop, but that's not happening either. I would also expect UI designs to be merging where innovation is concerned, say if they invested in better desktop/window manager UI, but in actuality all that is happening is the backporting of iOS ideas that are all centered on the fullscreen mode.

> I wish they would spend time looking at some of their interface changes and really work extra hard to help non-techies "get" them

In my experience that's not really a pain point. I have seen several of my clients adopt an OS X-only landscape in their offices (mostly non-technical people). I feel Apple is actually making heavy inroads in office and home use, but for many reasons is losing the support of technically-minded people who - at the risk of sounding self-absorbed - are early warning indicators that the base of the platform is withering significantly.