Gibbs notes the arrogance. You have to be arrogant to lead a mutiny, even if you think there is just cause. And he sees the weariness. Does Barbossa perhaps regret his choices in retrospect.

He could argue that Jack is the finest captain he's ever known. He is smart enough not to enter pointless debate.

"There are other methods for replacing a captain. And the timing, if my understanding of the tale, is rather curious. Seein' as how Jack trusted you and the crew with the one secret he rarely trusted anyone with, all these years.

"Not that you didn't do him a favor by sending him away from the curse."