Long time ago you were able to faint with help of switching between melee mode and shooting mode and faints were actually hard to block. Since bayonet in NW has only up and down attack its pretty easy to block so blocking is not challenge like in Native. Double-xing would bring many effective faints and would make blocking more of a challenge. Also it took a lot of skill to perform best double-x faints. Currently melee is just to much about all kinds of chambers and range (that includes footwork). Just because it was a bug in-game doesn't means you have to fix it, if it made game better then leave it be.