Quoted from aerobert:I showed my colleague who is a mechanical engineer my pinball machines. He's 28 or 29 years old and was never into pinball. Brand new world to him. He shook his head and chuckled and could not understand all the solenoids and different mechanical solutions. Everything was so archaic to him. He asked similar questions, why sensors, electronics and servos and stuff wasn't used instead to have more controllable logic without high voltage stuff. I honestly could not answer him.
Servo driven flippers would be neat but I'd like to see your friend come up with a solution that can match the torque, speed, and cost of a solenoid.