Personally, I think you're giving too much credit to the Amiga when you claim it to be that revolutionary. Apple likes to stake this claim too. In the end both derive most of their inspiration from Xerox PARC and Xerox's over priced $14,000 GUI based systems (which preceded both).
Now all common personal computers use a mouse, have a GUI, and a multi-tasking OS. But that's not Amiga's legacy (or Apple's), that's due to Xerox.
This has to be the most rabidly contentious thread yet. AmigaOS, OSX, Windows, Linux - what's the difference?