That's not a bug, it's a feature! Nothing like curveballs to spice up your shooting. It probably looks straight to the server, but your client is compensating - that's a guess, but your archery is going to be guesswork anyway. You can do this with throwing axes too - a nice C curve.
Now, as an archer, not only are you slower then a corpse, you get to rely on shooting 'somewhere' as your defense against a charging enemy. But we sure got rid of those twitch shooters! Rather then being actually nervous when charging an archer, you can simply be somewhat annoyed.
The real effective archers and xbowmen are virtual turrets. Oh and horse archers, who probably still have that extra power draw they got, because you have a more stable shot as a Khergit horse archer then as a Vaegir archer.
There's already a thread or two regarding the turning penalty. It would have been easier to leave aiming alone and reduce the stack sizes of missiles and thrown weapons, rather then nerf every throwing weapon and missile in the game, but some people don't want to get shot at all.
You should try melee, it is quite fun.