Mad Jock,
I don't disagree with what you are saying but as pointed out we are talking about IFR training here, and whilst you do have a duty of care to look out you also have a duty of care to follow the SID or approach plate, One person flies the aircraft the other monitors not only the PF but also out the window..
The real issue here is, as I pointed out if you do your IFR training in VMC or IMC it shouldn't matter as you can't see out the window as a pilot flying, it's the instructors responsibilty to keep a watchful look out.