Ignorant accent

Why does the the Guardian continually refer to the US detention facility in Cuba as "Guantánamo"? Are they trying to show off their knowledge of Spanish by adding an accent to it? Who knows? But all they manage to do is display their ignorance.

Just to be clear: "Guantanamo Bay" (no accent) is the proper name for the US naval facility where the detention camp is based, it's not a misspelling. "Guantánamo Bay" (with an accent) is the name for the stretch of water on Cuba's southern shore.