I think that some fans are sick of there being no continuity of style at the club eg Louis Van Gaal plays possession football so he needs certain types of players to fit his style, then Jose comes in and wants to play counter attacking and some of those players don't fit his style, so he wants players to fit his style. This has resulted on millions getting spent unwisely. Then Ole comes in and he is stuck with the remnants of both eras. At least when we have a DoF he will have a certain style and then the next manager hired will be one that plays that style of football breeding continuity, which we severely lacked these past few years.
Obviously a new manager comes in he is going to want his own players but having the DoF and style in place and securing a manager who plays this style, is going to lead to less of a need of a major overhaul, saving us millions.
Obviously there is going to be a chance these players may fail but at least having a distinct style and buying players that fit that style, in my opinion means there is less chance of that player being a failure here. Also if we have a DoF in we will have a man who has a good level of knowledge, one who Woody should listen to the opinion of. As of the moment it seems that Woody thinks he has enough football knowledge to judge which position we need to sign a player in or not, when to me it seems as if he doesn't have a clue, when we can all see the areas that need improving in the team.
Obviously Woody is still going to have the final say on transfers but hopefully when/if we get a DoF he will decide what players we need and then the only involvement Woody will have in the the process is negotiating the fee and wages of the player that the DoF and manager have decided will improve the team.