You are reading me wrong, I'm not "changing my ideas." The power isn't necessarily generated by the upstroke, and I never said that it was. But the upstroke is crucial in keeping the momentum of the pedalstroke. Pulling across the bottom and up are both important.

Bottom line is that without being able to lift up on the pedal it is not possible to generate as much power as otherwise in a high force application such as a steep climb at a low cadence.

And you still have not provided any qualifications that would make anybody take you seriously.