Except that it's a variety of cheese, which is more like saying only one company can make bicycles and anyone else has to label them "pedal wheelers" instead.
Your post also assumes that no bad sparkling wine comes out of the Champaigne region, and that no sparkling wines made elsewhere are significantly like the sparkling wines of the Champaigne region. Which are pretty big claims to make.
EDIT:
I've realized where I'm coming from with this: I fucking hate when someone tells me what to think and what to say, and when a pissy little bastard forces everyone to scramble around at his pleasure.
If I want a bottle of champagne, that is, lowercase champagne that didn't come from the Champagne region of France, I'm still gonna call it champagne and I'm gonna expect to see the word champagne on the bottle. Fuck Champagne and fuck all the pissy bastards who want the rest of the world to conform their thoughts and speech and product labels to their desire to sell more of their local product.
There are apparently 1.3 million people in that region, and they can all just suck it. Learn to live in a world where you need to read the back of the label to find out where something actually came from.
You could argue that it's false advertising, but I don't think ANYONE believes their Swiss cheese came from Switzerland, that their Greek yogurt came from Greece. People who care look to the country of origin, the vineyard, etc. and if anything enjoy discarding an "inferior" product back to the store shelves - a wine probably all but identical to the one they spent $40 more for.