nobody would want to program something like a GUI based operating system in assembler!
Take a look at http://www.menuetos.net
and be amazed :o
Looking at the output of ps axl
on my Linux box and realizing that I have no idea what half of the processes are doing, it easy to see why I like Arduino.
My nick "drhex" comes from the days when I wrote Amiga Assembler in straight hex code as data statements in a basic program, because I disliked the Seka assembler... Got it to do mandelbrot calculations at 10000 iterations/second when compiled C with the floating point libraries did only a tenth of that!
Now with Arduino, I can have detailed clockcycle-control again!