Reserving the name Champagne to a specific region of France is a fair trade practice. When you permit only a certain region to give their wine the name Champagne, while that may slight other grape farmers who are not in the region, it provides a valuable opportunity for the farmers in the region to provide for their families.
The French name "Champagne" should be reserved for the French because the term is a product of the spoken language of France. The fair trade practice is more concentrated in economics instead of semantics. In regards to semantics or linguistics, the French name "Champagne" should be reserved for the French.