I'm wondering why this mechanic is in the game; is it present in some other games? Why does the first shot cause a larger kick? Does it represent the soldier shooting, and the first shot he can't pull down as well until there's a steady stream of them? Are there any other hidden factors to it? The Anchor has a high 1st shot multiplier than the GD-22S, with the same normal recoil pattern afterwards, but it does seem to have much more of a crazy kick to it? (or should I try the Anchor with a grip attachment?)
It's present in nearly every single ADS shooter. I can't tell you definitively why it exists, all I can do is provide you conjecture and speculation. It might exist to offset the advantage of burst firing, because without a recoil penalty like this, it would be very simple to just single tap at extreme distances with crazy accuracy. Or it could be to simulate the "unpreparedness" of a soldier of beginning fire like you said.