Because it accomplishes nothing. It will do nothing to hurt the Red Sox chances. They'll pull him back and ship him to the Mets at a later date. What it does and why it is petty is that it will screw over Carter by forcing him to stay in an organization that has no plans for him, and time is running out on him. He's getting a little long in the tooth to be considered a prospect. If the Yanks had let the deal go through, he would have gone to his new team which is so depleted that it would have been likely that he would have seen some September major league playing time. They screwed him over big time.