While I understand your point, I really hate the idea. For one thing, it wouldn't really work. With all the hacking, there would still be tons of legendaries out there- fake, yes, but still present. And as a more personal thing which I am sure I am not alone in, there would almost no way for me to ever see one- I don't have wi-fi, and trying to find someone irl to trade with would be awkward and nearly impossible. One more thing, I thought, correct me if I'm wrong, that the anime/ manga (?) kind of says that there are many of each legendary- you were just lucky if you even saw one. <-- I think I read that somewhere, but don't take my word for it.
Besides, if people just stopped cheating, legendaries would become more legendary.
(Sorry if that was really mean; I don't know why I care so much, but I do. :))