By using this treasure to enter the Tail Demise Palace, one can "act with the flow." However, James's previous owners couldn't control their greed and, despite knowing that they shouldn't "act against the flow," still wanted to "take a chance" when they saw some precious treasures.
James had an extremely high intelligence, otherwise he wouldn't have come up with the plan to "revive" ancient cultivators. But due to his limited cultivation realm, his true understanding of the rules within Tail Demise Palace was far less than that of Master Sun. So the Duster transformed all the rules into a pattern that was easily understandable and fed back to James.
If Master Sun had the Duster in his hand at this moment, he might indeed be able to find a way to "act against the flow." But James didn't have this ability, nor was he greedy. He only wanted to take advantage of the situation and obtain what he desired, not taking any other treasures.
