What disappointed Columbus about the new land?

Columbus had gone west to find a short route for the very profitable spice trade. He was (and remained all his life) convinced that he had reached islands off the coast of India and was much disappointed that he nevertheless found no trace of the hoped-for spices. There was however a - fairly modest - amount of gold found on the islands. Columbus had himself appointed Governor and instituted a reign of terror, robbing the islanders of every ounce of gold they had and setting them to work as forced laborers in the mines. The cruelty of his methods created such a scandal at the Spanish court that Columbus was relieved of his Governorship, arrested and brought back to Spain in chains.
He didn't find gold or other treasures.