Columbus was wrong. While the grandparent posits a hypothetical where there was no land in between, that's not what Columbus critics suggested -- they suggested that the known size of the Earth was such that a more economical route to the Indies from Europe sailing West was not a reasonable thing to expect.

They were correct, and Columbus -- who insisted that he had reached the (East, now, because of the confusion he caused) Indies -- was wrong.

Columbus wasn't looking for America. He had miscalculated the circumference of the earth and thought he could sail west to India. The Portuguese laughed him out of the country because of this. Note that the Caribbean was called the West Indes for this reason -- Columbus thought he had hit India.