The only reason it seems OP is because so many people use it, and when you constantly get killed by it at close range you get pissed. I rape people with the Stoner63 or whatever and I personally thing it is better than the Ak74U.
Anyway, the AK74U is way overused and is not overpowered at all. It is just better at short range then an assault rifle. So Famas agains Ak74u at close range... famas will die. Famas against Ak at medium...an equal battle... Famas against AK at long... Famas will no doubt win.
Since most of your encounters are med-long range on BO, and since the AK is so overused, it almost seems like you are constantly dieing by it. It is honestly no better than any other med-shot range SMG. For example, the spectre. It is an amazing SMG.
You also got to take in account for what you unlock and when you unlock stuff. The AK74U is the best SMG at the lower levels because you unlock it fast and it is the only good one for med-long range when you unlock it. Many people use it, because it's familiar from all the other cods, and get well connected with it. They get good with it and like it so much they'll probably use it until they prestige. I guarantee if the spectre was unlocked at level 16 then everyone would complain how OP it was.
You must take in account for many factors before you say a gun is OP. The reason the akimbo models where nerfed so much was because they were by far THE BEST shotguns in their class. The AK74U certainly isn't the best SMG on the list, so they will not nerf it anymore.
Just because so many people use it, doesn't mean that it is OP. It is way OVERUSED.