Make no mistakes. The reason the melee weapon in shooter games is always the strongest is because they want to emphasize that it takes a certain amount of skill to take an enemy out up close like that. Problem is, this tends to result in balance issues with the game play.
It is just odd to see a solider take nine slugs to the chest in a shooter game and keep going only to be fallen by one stab from a pocket knife. Apparently we are NOT the super soldiers we think we are. At least when it comes to the intimacy of the blade.