I wouldn't have made McGinn captain last year (i think most of us would not have), and I don't really see McGinn as the true captain of the squad currently.
However, we definitely don't need another debacle like Stevie had stripping Mings of the captaincy right before the season, so I don't really see a point in taking it off McGinn to give it to someone else. It would just cause more news and scrutiny on the players.