That is what the extra CB is for. THey are there to defend, but they are also two big parts of the attack. Blind bombed forward against Spain and it was the difference between Robben/RVP having service and not having service. There is no point not attacking, but also remember that Kuyt, regardless of what defensive duties he had, had LOADS of the ball in and around the final third. It's got nothing at all to do with his defensive duties. People are using the fact that he's being asked to defend more than usual.... as a reason that his crossing has been worse than anyone else in the tournament, that when he has the choice of trying a throughball... he usually passes towards the centre circle instead. If he actually never got over the half way line... some of the excuses being made in this thread would be relevant.
When he's on the edge of the box he's not in an unfamiliar position, nor is he defending. His woeful crossing is nothing to do with what position he's playing. His choice to kill every counter attack with either a pass backwards or a crap cross is because he's ****, not because he's a wingback or has defensive duties.
Yes, Janmat was a sub and had more energy, but Kuyt bombed forward all game long...... it's what he did with the ball that is the problem, not where he went. Against Argentina he probably had more touches than Sneijder, RVP or Robben in the final third... and the reason no one ahead of him had almost any touches was his woeful play from that point.