I think the obvious answer to that is that agents will flog their players to as many teams as possible. What that does is hopefully spark a bidding war and the agent either gets his client a payrise at the club they are currently at, or at a new club, and the agent takes a cut of that either way.
In my opinion this quote highlighted a bit of Ole's naivety, and inexperience of being at a massive club. Of course agents want their players at united, we pay the most money for players, its a pay rise just to be linked with United normally.