Wow, Hilderman's quore is just factually incorrect where he says:

"Fuel is 20 times more than the passenger weight"

For most transport aircraft, passenger mass fraction is roughly 12%-18% depending on what's included (cargo, seats, etc.), while fuel mass fraction is around 30% to 40%.

So this ratio is more like 2 or 3, not 20.

Passenger weight is absolutely a huge factor (speaking as an aerospace engineer focusing on vehicle design and flight performance).