Can't say I experienced that a lot but here is the thing: Usually people who do the "dance" (me as well sometimes if you check out my youtube vids) don't actually shoot while moving. You stop for a second, shoot, then keep moving. Now you might say: Well, maybe deviation should take longer to settle after moving.
Thing with that is: It used to do that, but it sucked. Due to there being no cross hair and no real indication in iron sights, there is no proper way to communicate to players when your deviation is back to normal. In FH1 much of the shooting skill involved waiting for the cross hair to "close", but this dimension is gone in FH2.
So back in 2.0, many people complained about not being able to hit the target, even though they were aiming straight at it with their iron sights.
Because of this, it was changed to the current system, which itself remained unchanged since 2.4 because people are largely happy with it.