AIRBUS not really to blame : if you bring your car to the mechanic and he make a mistake, do you criticise the car maker?
As a previous engineer on A320, I have never seen a side stick (which is flight control and I guess vital component!!) be replaced with a check consisting only at a glance on a screen.....we always had a look inside at the screen and outside at the controls to check for proper deflection and that was mandatory!
And as a private and line pilot, I always check visually the controls through the window BEFORE departure, I guess to what I see for real, aviation related matters speaking.
Haven't you ever experienced a problem with your home personal computer that you nor the specialist could explain?
And beside this, when you look at a screen to check an indication, there is a lag effect, in that case, the aileron where moving in the correct direction then after the lag they came reversely...If the pilots or engineer would have checked wih their eyes directly the flight controls, they would have seen the misbehaviour!
The F/O had the flight back to control seconds after TO which is sure very well done BUT there have been a chain of error that could have been broken before TO with an visual eye flight control check.
Human make errors.