conductors

what is the point of musical conductors? i'm talking about professional, full-scale award-winning orchestra conductors? i don't see how they do anything useful. i have also recently seen Leonard Bernstein do conducting, so i have a little exposure to it (admitted emphasis on little). it really seems like they are only there for the audience's enjoyment. the musicians at that level are ridiculously well-trained. you don't see the conductor telling one section to be quieter, or another to play faster, like you might in a high-school ensemble. and the conductor doesn't even keep time, his arm movements are mainly flailing and expressive, not actually what i would call useful. in fact, all of the directions for the musicians are pre-written into the music, by the guy who wrote the damn thing. it tells them where to speed up, do staccato, pluck, bow, suddenly get louder, the works. and by the time they're performing, i imagine they've rehearsed so many times that the physical sheet music isn't even needed. i would refer people to the scene in mr. holland's opus where richard dreyfuss pretends to conduct (and of course it looks pretty good, because conducting is only pretending to do something useful anyway), and his deaf son keeps conducting along with him after the music has stopped, although also doing a fair job along the way. but i don't want to be too much of an a-hole. party alla time.