Weight training for basketball

As long as it does not interfere with flexibility and mobility, strength in basketball is a good thing. However, it always puzzles me why athletes apparently spend so much time on their biceps. Because bulging biceps look impressive, no doubt. But how much do they help in basketball? Some, no doubt, but my meager knowledge of anatomy suggests that there are other muscles that are used constantly, the development of which would be much more important to a basketball player - or most other sports, for that matter. I wonder how sport-specific weight training is. Do they analyze the specific motions of the game and develop the muscles that control those movements, or do they just go through the normal weight lifting regimen? I do not know.