Technically he did. Just can't perform all those abilities because of alignment.
George Lucas disagrees with you he layed down the law that you cannot master both light and dark g canon overwrites whatever is said in the revan book so revan did not master both since its impossible.
What revan did was become one with the force which is not mastering both light and dark hell revan was not even a master of the dark side or light side. What made revan amazing was his leadership abilities and his charisma not his prowess with the force.
If the exile was not there revan would of been killed by the emperor.