This game requires precision aim and you need to understand how the recoil on weapons work. On top of that you have enemies have helmets and things you hit instead of just being able to blast anywhere in the head and get the instant kill you're so used to.
Games such as MOH, MWF, BBC, are all unrealistic in this aspect, so those people all got thrown for a loop when they encountered this.
The weapons and ammo aren't underpowered it's just you're not used to the way the game is and you all do not realize you have had it too easy in your war games.
I'm not trying to be a [censored] or anything but this game will/should wake the people up who aren't prepared for this type of realism in a game and make you appreciate how easy you actually do have it in your wargames and other games like it