Well, first there's the fact that "the Middle Ages" is an ill-applied term in other continents. And in China, for example, the High Qing period of the 18th century is generally considered a golden age, an era when China reached unprecedented territorial extent and a period when great works of literature and art were made. The celebrated splendor of the Mughals in India comes well after 1500, the Ottoman Empire continued to expand and thrive to the point of besieging Vienna in the late 17th century, and new players like Asante entered the complex game of politics in West Africa.
Could you clarify what makes you think this is the case?