Proved to the skeptics that the world was round by trying to find a new way to India.
Yes he was not a good person to the natives. But there was far worse persons than him.
His search for riches was in vane. But he paved the way for the Spanish to conquer Central America.
He tried several times to find a short cut to the Pacific Ocean. By which he mapped most of the Caribbean Islands.
He died a broken and poor man. Never finding a short cut to India.
If he did not start the new discoveries who knows who else would have. But he was the one that stepped up at the time and started the new wave of exploration.