Not familiar with the culture or mindset, but I'm guessing it's simply because "you're fired because you intentionally didn't do your work" is easier to accept mentally / emotionally then "you're fired because you're just kinda stupid and slow."
Yeah, that's in the same vein as to what I was trying to get at. Being fired because you refuse to do stupid make-work is certainly less psychologically damaging than being fired because you were no good at your real work.
