Utican, I think you're making a valid point if i'm reading you right.
In a *true* survival situation, your survival instructor taught you to cut wood by simply using it in a fire - meaning don't cut/split wood unnecessarily like as you mention to make planks. Definitely! Why expend the calories/time if you've got a fire going?
I agree with this wholeheartedly, but i wonder if in your survival class an important aspect was missed. The value of batonning is, as mentioned, to get dry tinder to start the fire. I wouldn't necessarily baton a 6" log unless it was only thing around - unlikely, but not impossible - UNLESS the wood is pretty wet and you need some bigger dry stuff to get it roaring!
I'd check out youtube icychap's video on his Trailmaster improvement - he illustrates excellent batonning technique. Here's the link:
http://www.youtube.com/watch?v=D2rtkheMo2I&feature=related
His demo is at the end of his video, but it's well worth watching to see it done right.