I really like this feature, unlike most of you I guess
It adds the element of surprise to the game. If you found out that a player was going to sign with you before it happened, then you could sign just about any player you wanted, as long as your team was good enough. The fact that a player will sneak behind your back and sign with someone else last minute, prevents you from stacking your team, and adds a little mystery to the game. Not to mention it adds a great rivalry with the team he signs with