Who Cares Who Discovered America?

So the president of Turkey says that Muslims discovered the New World before Columbus did.

Turkish President Recep Tayyip Erdogan said Saturday that the Americas were discovered by Muslims in the 12th century, nearly three centuries before Christopher Columbus set foot there.

Yawn. It might well be true, I suppose, though it must have been crowded on the beaches, what with the Vikings, Irish, Chinese, and various others all taking turns discovering us.
But, if it is true, or if any of the other claims is true, so what? Given that it's un-PC to celebrate Columbus Day anymore, are we really supposed to even care who discovered the continents? As a matter of fact, I think it may even be un-PC to refer to it as 'discovery'.