“It hasn’t been patched yet” - ??? It is a feature these systems have in real life, not a bug. Go check the devblog on it.
Also, the feature is a gimmick; the area that multiple guidance beams can be used is a narrow sector (both horizontally and vertically limited) and the auto guided missile is unlikely to hit a maneuvering target. The ignorance in this thread is astounding.
Because the NATO SAMs currently in the game don’t have the capability in real life, and there is no variant of them that does, to my knowledge. Not to mention this gimmick is obscure in the face of top tier fire-and-forget SAMs for every single nation.
And when NATO systems do have the capabilities in real life (Spikes, NATO MBT armors, NATO APFSDS pen, …), they’re nerfed and don’t perform as they do IRL.