The question you have to ask yourself is if the act of creating that extra 10% power cancels itself out in other ways. Bear in mind a couple of things. We know that adding small ammounts of power has diminishing returns because aerodynamic drag increases in a nasty way. The increase in drag from say, 15mph to 20 mph is more than it was from 10 to 15, and so on.
Now remember we suffer this effect much more than we're used to thinking about, because a bike with a rider is just about the least aerodynamic thing. A brick with rounded edges would do better.
Now start pedaling fast, and suddenly that extremely unaerodynamic object has gotten even worse. It won't even stay the same shape, so the drag goes crazy. If you ever watch cycling on TV when they're going down a mountain, you'll notice they stop pedaling and put their feet level at 9 and 3 on the crank. Their speed is entirely within their gear range, but they stop anyway, because the aerodynamics mean powering themselves would be slower than just tucking in and letting gravity do the work.
The top speed of a decent ported out motor with the vibration taken care of is what, 40mph according to your own figures? That's well in the speed range where trying to assist the engine is just pointless behavior.
As for chains dropping on a 1x, I have to say that yeah sometimes they drop, and sometimes wheels fall off too. I don't have special wheel-holder oners though because I know that'd be an exceptional situation. Tighten your wheelnuts, make sure your chainring isn't bent and stop worrying.
Well he's not worried about it because he's not riding a single speed, and I've seen more chains drop than wheels falling off than I could imagine, which come to think of it I've never (personally) witnessed a wheel just jumping off a bike.
An extra 10% power doesn't cancel itself out, it gives 10% more power which let's you go faster untill the new level of resistance zeros out the forces involved, regardless if it was a 10% or just .1% increase in speed it can't simply be a 0% increase and certainly not going to be a decrease.
You seem to presume anyone with an engine is going to use it at its maximum output, if you look at the electric bike world it's almost the opposite trend, where you are actually assisting the motor or depending on how you look at it the engine is assisting you. The point is that you don't depend on the motor as the sole power source and so you just don't think of it like that. Fury just wants to demonstrate that (since these are f***ing bicycles after all) you can keep a system that will let you actively assist an engine in propulsion, even if it rounds in its power at 40mph on a single gear drive. The more calories he burns the less fuel spent, nothing wrong with that.
Using gravity as part of your argument is pretty much the same as saying 'Hey, you got a motor to accelerate, why pedal at all?!' It doesn't tie in well with your aerodynamics argument since those people don't even have an engine to accelerate themselves along with their legs, and since using their legs would provide an equal or lower return to just letting gravity do the job they obviously let gravity do the job! You as a person can more or less achieve the speeds gravity will take you to, and since the engine can outperform both you and gravity that means that, especially on level ground, there is an advantage to pedaling with the motor.
To put it quite plainly, you + motor always = more power than just motor. You can't argue against that. Guys just pedaling have to consider that they can and should reserve energy when possible, with a motor the need to prevent yourself from over exertion isn't there, and chances of it are highly reduced.
You have to ask yourself why you are arguing against a 10% power increase just for the sake of it.
