Public reason: "We have listened to your concerns, we agree that something needs to be done and we trust you to be that person".
Private reason: "We have been irriated by your incesent whining, we are going to sack you from your current position, then offer you the choice of being shut up or facing a drop in salary. *Evil Cackle*".
Please note, the above may be a total fabrication, but then again...