In the context of sprinters, especially sprint cyclists, athletes do train for bigger muscle. Those that don't (if there are any) should. As Andy pointed out, weight training leads to hypertrophy which in turn leads to more power. Purely training neuromuscular power (as opposed to hypertrophy) with weights is fruitless for cyclists as it is very difficult to replicate joint angles and velocities appropriate for cycling with weights and neuromuscular adaptions are highly specific to joint angle and velocity. That said, I know strength coaches at the AIS still make the effort to go as close as possible to the same joint angle and velocity when using free or fixed weights. There is a great post which talks about this on one of the track cycling forums. Andy linked to it on another thread on cyclingforums, so maybe go looking for it here.