You seem to have it backwards, and here is why.
When players require more bullets to take down, (like in Brink)
- simply getting off the first shot doesn't determine the winner.
- firefights rely more on the skills of person vs person, rather than "who shot first." - in other words, it takes far greater skill to "duke it out" with an opponent and come out the victor, than it does simply putting 2-3 (or less) shots in him, usually from a camping spot or long distance.
The fact that you only have to it the target 1 or 2 times, means accuracy is less important - its common sense. Players don't bother aiming for headshots in these games, because they are dead in so few shots anyway, just making contact is sufficient. Yet with the shooting mechanics in Brink, not only is accuracy and shooting skill much more important, since aiming for the head or body can spell the difference between winning and loosing, but simply getting the first shot off, doesn't guarantee you victory. The longer it takes to kill someone, the more important movement and aiming become. When kills take very little time, the balance shifts towards positioning and being the first to shoot - This is also common sense.
In games that require few shots to kill, there are 2 ways to improve your chances of winning. First, you can practice hard and learn to move fast and when to move. You can improve your aim and reactions so that you can aim onto anyone you see. OR you can find a position that is hard to spot (with decent cover) and stay there, aiming at the entrances or exits to your location so that you see them first every time and don't have to aim, as you are already focused on the narrow door they will be coming through...
Obviously, most players choose the second option, since it is easier and takes less effort and concentration.
The main point is that games that require a small amount of shots to kill, promote camping and cater to casual gamers. This is a reason why COD MP is so hugely popular - because you don't have to be that good of a player to be good at it.
Is COD popular? Yes
Can you be good at it? Yes
Can it be played competitively? Yes
Does that make it a good game? No
Does that mean that COD's damage scales are the best? No
Chances are, all thees people who are complaining about it, are just upset because they have to work for their kills now.
Also, this can be interpreted in different ways. When Richard Ham said it takes about "half a clip to take an enemy," He could have meant that it actually takes half a clip's worth of bullets to kill someone, or he could have accounted for people not hitting every shot, and/or not going for headshots, and stating that the average person will take half a clip to kill someone. There also isn't any clarification on what size clip he is referring to.