Not saying this is 100% correct, but I'll take a stab at it.

I'm pretty sure it was removed because it was causing the server to figure out your position slower, as well as making movement feel... sluggish. Need to quickly move out of the way of Ifrit's Eruption? Hold on there... accelerating... moving... decelerating... BOOM! When fractions of a second count, sometimes you have to sacrifice some realism.