OK, so here's what Moby's argument boils down to (if I understand it correctly):

The plane can't take off because the rolling resistance of the tires on the conveyor and the friction of the wheel bearings resists the plane's movement through the air enough to prevent it from achieving enough airspeed to take off.

Essentially, the wheel bearings and tires are acting like big parachutes behind the plane.

The plane may actually move down the runway (it would have to have some kind of forward motion because otherwise the conveyor would also stop moving) but it'll just reach the end of the runway before getting airborne.

So, the issue essentially is that we'd have to know the design limitations of the tires and wheel bearings in order to know their maximum safe RPM before self-destructing.