Just to play devils advocate here. The most used knives in the world of professional chefs are Victorinox, and that has not much to do with excellence in steel or sharpness. It has to do with the fact that Victorinox has been very successful in pushing out knives set (suitcases with basic, intermidiate, and advanced sets) to pretty much cooking students all over 
They can get away with a basic suitcase for the same price as two Kai Shun knives...
That's a fair point. Popularity doesn't prove superiority. Indeed, I think most photographers could quickly adapt to systems from any of the major camera makers and produce equally good work. Likewise, the work doesn't prove superiority, as the Nikon and Canon pictures in the set are of equal quality.
However, I'm not sure how far your knife analogy extends to the camera world. I'm not aware of Canon pushing out super-cheap gear to photography students. There may well be a deal between them and Reuters, though clearly some of the photographers are still shooting other brands notwithstanding any such deal.
I am aware of huge student discounts offered by Adobe on their software. At the same time, many professionals would buy Adobe's Photoshop and Lightroom without ever having received a student discount.
