A good point - but one we have considered thoroughly!
The real flight-controls in a Boeing (and any airliner) will only move so fast - the hydraulics can´t move them as fast as a pilot could throw around the control wheel/sidestick. In Boeing aircraft (at least the ones I flew) the flight-control inputs are connected proportionally to the flight-control surfaces. This means that you can only move the wheel as fast as the controls move.
This is great, because the pilot always FEELS what the current displacement of the flight-controls is like - very important in windy/gusty situations where overcontrolling is a real threat.
Airbus does it differently - here you can throw around the sidestick pretty much as fast as you want, with the flight-controls lagging behind (and the computer in normal law also messing with you). Thats why Airbus aircraft are (in my humble and personal opinion) a nightmare to fly in gusty crosswinds. Sorry, Tolouse.
For the IXEG we have the same problem - the user can throw the joystick from side to side in 0.2 seconds, while the flight-controls take a lot longer. So we had a choice to make - but if we made the flight-controls stay in sync with the joystick (which leads to better control), we would have had unrealistic roll (and pitch) rates - which is a no-go!
So until we all get force-feedback hardware inputs, it´s just something we have to live with. But rest assured that the plane rolls as quick as in real life.
Cheers, Jan