They have many guns that are more accurate and have longer ranges/more suitable for different operations. The AK47 has had such a long life, because for poor countries, military organizations, and terrorist groups it is the cheapest and most reliable weapon you can get. They sell tons of them, so there is no reason for them to stop making them. Also the design is quite simple. If you change the weapon or design a new one, you will have to charge more for it. Do you think terrorist organizations care? They just want a gun that will kill you from more than 20 ft.
Okay, I think this conversation could be carried on in the other AK47 thread. I realize they're two different ideas, but I'm sure we can figure it out.