I'm sure the Amiga UI was heavily influenced by Apple's at the time. They also did a lot of things in a very similar way. Look at how icons appear on the desktop when a floppy disk of CD is inserted. This works in very much an identical way on both systems. And actually, when I moved to using PCs this was one part that did really annoy me. I wanted Windows to work like Workbench/Mac OS in this regard, instead of the My Computer window to access devices.

However after some use you get used to it, and it has its own logic, keeping devices all separate and in one location. And since haven't minded either method.

It is true that OSX and Windows are converging in ideas and UI, but then this is going to happen eventually with any products developed in parallel as technologies progress and ways of working logically slowly converge. Will we ever end up with just one single OS all systems are running on? Not any time soon I hope because competition breeds progression, development and innovation. Also server OS's can't be the same as desktop OSs.