Oil has its own infrastructure. That infrastructure is producing things for airplanes almost as a byproduct. Both of the oil we pump from the ground goes to cars. If cars switch from using oil, that's going to raise the cost for everything else to get the oil they need because they have to pay for the full refinery output. Or in this case if airplanes quit using kerosene for jet fuel that is going to slightly raise the price of refined oil for everyone because the refineries don't have that one small extra part of their income sheet to help pay for the fixed cost of having a refinery. The whole system needs to work together, of course. If only airplanes get off, the difference is merely insignificant. However, if cars and airplanes both get off using oil, suddenly the other uses of oil become unfeasible.