Since Barcelona bought De Jong, I have not seen any of his contributions to the club, he's currently out of their squad due to an ankle injury, I don't even remember when last he played for Barcelona because he usually picks up injuries.
Although, he's currently faced with injuries but even with his injury he did contribute to the team (greatly)before his last injury so taking a proper preview will help incase you need to verify .. Dejong is a great asset to Barca that's why you won't hear them discussing about either he should be sold or not ..
The club itself is full with a lot of players and some are not even contributing at all just as you've said so it will be a good idea to flush the team and bring in new experience players to guide the signed academy players because barca is planning on using more of it tamasha players.
About Xavi, he favourites players most times which do cost the club some loss, i just hope he learn from his mistake because I don't know what Ferran torress is still doing in that club till now