Also his intended destination was real and the science for a round Earth was not phony.
I think later centuries owe a huge apology to the poor people of the 15th century for shamelessly replacing them with straw men. They never claimed the Earth was flat. That's just silly. It was Mr. Columbus who ignored the scientific knowledge about the Earth's roundness to support his mission, not those who detracted his flawed ideas about the location of Asia which did not exist where he was headed. Something everyone knew, except Columbus.
That's what your own link says:
Washington Irving's 1828 biography of Columbus popularized the idea that Columbus had difficulty obtaining support for his plan because many Catholic theologians insisted that the Earth was flat. In fact, most educated Westerners had understood that the Earth was spherical at least since the time of Aristotle, who lived in the 4th century BC and whose works were widely studied and revered in Medieval Europe. [...] In Columbus's time, the techniques of celestial navigation, which use the position of the sun and the stars in the sky, together with the understanding that the Earth is a sphere, had long been in use by astronomers and were beginning to be implemented by mariners.
Where Columbus did differ from the view accepted by scholars in his day was in his estimate of the westward distance from Europe to Asia. Columbus's ideas in this regard were based on three factors: his low estimate of the size of the Earth, his high estimate of the size of the Eurasian landmass, and his belief that Japan and other inhabited islands lay far to the east of the coast of China. In all three of these issues Columbus was both wrong and at odds with the scholarly consensus of his day.
He got lucky that he found the Americas there. But if the Pacific and the Atlantic had switched places, he would have found only disappointment.