I find it hard to believe that this was the intended implementation of the sounds in in game.
To say that removing footsteps altogether, which is what has been effectively done (since ninja PRO barely makes a difference in hearing enemies sprinting around the map), is in anyway a rational response to 'soundwhoring' is ludicrous...In a TACTICAL game, in ALL tactical games so far, and in all that will follow, the following paradigm exists: You run, you will be heard a mile away; You walk, you will be heard; You crouch and creep, you will be silent.
If this is a bug, please admit it and fix it when you can...The responses I have read from Vahn make this seem like it was intended, which I personally find hard to believe...It's game breaking...As good as Treyarch has been with WAW and BO, I find it impossible to believe that something this fundamentally vital to gameplay has been omitted deliberately. I understand this is not MW2, and it should not be ultimately based on it. The system they had in place with ninja/sitrep pro/normal class DID need tweaking, but this is going overboard.