the 3 round AR in BO2 was also the dominant gun in the game for accuracey and stopping power. It was eventually nerfed and required two 3 round burts to kill, basically at least 1 bullet of the second burst had to hit the target. The nerfing made the gun less popular in general play but becasue of the accuracy and burst fire it would kill instantly with a head shot and so was a powerful tool for those that knew how to use it well.
I would look see the MSBS nerfed at some point.
to add to that, when it was nerfed a good way around the burst fire was to get a 'foregrip' and 'select fire' so you can set it on automatic. you loose some of the accuracy but with the rapidity of fire it makes it deadly.
The problems not the gun or the burst.
Majority of the time, with average lobby connection speeds (at least in the NE, due to the lag comp I'm guessing), you don't even register but a single shot that kills you on your screen so you can't react.
As stated, you'll have similar results from any other gun with the burst fire attachment.
Replace the words 'Lag Comp' with 'Matchmaking' and your post would actually go from being totally wrong to actually having some merit.
You are blaming bad lobby quality on the wrong thing. Lag Comp categorically does not work the way you seem to think - this topic has been beaten to death on here. I'm guessing you are new?
All guns are connection based, the MSBS is no different. Sometimes it drops people instantly and sometimes enemies spunge multiple hitmarkers when using it. So I think DEVs really need to be weary before tweaking guns that are garnering feedback because of online gameplay (which unfortunately is never going to be perfect.)