Well, depends on how you criticize I guess.
Because some consider the weaponhandling in BF3 as good. But these opinions rarely comes in terms of realism but from how practical it feels. Has nothing to do with arma. So without an argument to why, criticizing doesn't really tell much. What makes good weapon handling? What has to be improved in the current one? - or rather, what makes the weaponhandling realistic because that's what is important. Realism is priority one.
There is so much that goes into arma that other games completely miss. Despite the somehow clumsy movements this is mostly because the game uses realistic motion captured animations. How the game is built is totally different from any other games. Stuff like weapon discharge effects, sounds effects, accurate tracer ratio, accurate starscape, variable sea states, accurate moon phases (and how it affects visibility at night), simulated pupil reactions (for instance; when you look into a light source) proper weapon modelling and range etc, proper speed of sound modelling (for instance: you can see an exposion before you hear it) and sound occlusion (which makes sound be affected by the surrounding landscape).
Then there is a lot that goes into that. Bullet drop is for instance dependent on the caliber, and you have to calculate muzzle velocities (how fast the bullet travels when it leaves the gun and how much speed it lose for each meter). The bullet impact is also modelled, and how the ricochet occurs is regarding of surface (grass, stone, concrete etc) and the angle of the impact.
The you have the huge maps with 10,000km draw distance, and rendering of everything that's in it, aswell all set waypoints, the AI:s ability to be autonomous while you play, changing weather, and often huge amounts of NPCs, vehicles and all that. I can't imagine myself how much that goes into all of it. I do realize that it must be incredible hard to work with a game like that since everything has to be tested. And before anyone say that these things are not important, these are the things that the community care about. Even with all this its not enough and thats why increased realism mods like ACE exist.
There is no wonder arma is filled with bugs. What I hope most for with Arma 3 is that they manage to decrease the system requirements as much as possible and really push away a lot of bugs and glitches which will occur. Because there is no doubt the whole arma series is far from perfect. But I respect that. Operation Flashpoint: Cold war Crisis was released back in 2001, and it was far more innovative, bigger and way more advanced than Battlefield 1942, despite the fact that 90% of the game was created by a bunch of roughly 10-12 guys. BIS doesn't have the same economy as Rockstar Games, Activision or any other huge company and thats about it.