Probably because when implementing on the shop floor, various parts of DC need to be available.  This would give the floor the ability to view without being able to change.  
 
Whenever I want to do a "lookup" in WO, I use WO-A.  Very similar, but gives you the ability to edit.
 
I suppose you could add the DC-I menu items to your WO list if you wanted to.

I wish it didnt show cost and sell price
 
j Dub