For the same reason you can't start making adhesive bandages and selling them as Band-Aids, even though many people call them that: Both are proper names for a specific regional brand of sparkling wine and grana, or hard cheese, respectively.
One that's currently being litigated in the EU is whether labeling products not from Greece as "Greek yogurt" is misleading. I personally think yes, especially given the capital 'G' and the parallels with other clear origin-designating terms like "Greek wine" and "Greek olive oil" (and mixed origin/style terms like "Scotch whisky"), but it could end up going either way.
That’s what’s done here. You see that it is not the exact original product (sometimes you don’t even want the original product, but a specific fake of it), and you see still what it’s similar to.