Columbus was basically 'lost' in the  largest sense.   His accomplishment would be more 'monumental' if he had had more of a clue as to where he was!

And he was continuing the European conquest of the non-European  world which had been going on for several centuries by that time.  Holding him to our more effete standards of behavior some 500 years later is ludicrous in the extreme.  

History is history.  People like Selina Taylor need to learn from it and get over it!