Like you, I fail to see how anyone can respond to Spam but enough
folks do to make it lucrative - we still hear stories of folks being
taken in by variations of the Nigeria Spam even though it's widely
known about now !! As the man said "There's one born every minute" !

As for Apple - their insistence of micro-managing everything from
software to hardware to sales to support ( which they still do ) was a
major factor in their inability to compete with MicroSoft in the
emerging desktop market. I don't think they even want to get into it
in a big way - the move to the i386 hardware could have allowed them
to release the brakes a bit but they still hang onto the same methods
of micro-managing. Yes you can buy OSX but buying suitable hardware
for it to run on is still a bit 'pot luck' as you cannot buy the same
hardware that Apple uses.

Linux *is* the future, but the future may not be what many imagine it
will be. Will smart phones with projecting screens and keyboards /
alternative input methods sound the death knell of the desktop ? Who
knows, but the chances are they'll all be running Linux

Take your point about the sources of Spam - so really we only have
ourselves to blame.