What is memory protection and why is it so hard to implement for the AmigaOS?

[outlawal2]

If Apple can move from OS9 to OSX with compatiblity for OS9 applications (IIRC, it is in an emulation layer, but compatible none the less,) then...

Yeah and that particular implementation was REALLY well done IMO...  I have often hoped that the new version of AmigaOS would include support for multi-processors as well as good memory protection... It would really be nice since a rewrite of the OS is required to implement these items, then add these items and provide a modern OS providing backward compatibility similarly to the OS9 support model used by Apple...  

Sadly, I doubt this will ever happen and we will continue to have two very different camps with different goals...

[outlawal2]

That is true, but most of your abovementioned flavors were created with one of two things in mind..   Either:

Backward compatibility (MorphOS, Emulation users.)
Or
AmigaOS for the modern world and modern hardware. (supposedly)  (OS4)