I'm not saying that part is right or wrong, but if you think about it, making poor temperament a disqualifying factor isn't going to work.
Basically, since it's not something everyone can see, a judge can say "that dog has a faulty temperament" and boot it from the class, whether the dog really does or not. At least if it's something like color or marking that isn't up for debate as much (note: as much) then it's not disputable.
That being said, watching the video someone linked, I'm pretty at odds. I've seen a few Mals (at my SchH club) and none of them looked like those dogs really. Certainly weren't tucking their tails and acting skittish. But I guess that's the show/working difference, which saddens me.