I think the OP is right that society should prioritise which uses of fossil fuels should be focussed on for reduction. Heating houses and running trains could both have easily been 100% carbon free in many (certainly most western) countries by now if we had had the will to build nuclear power stations, and without needing the expensive battery technology road transport needs. Perhaps if we were in that position then electrifying road transport might be a sensible next step. However I don't think the current lack of any taxation for aviation fuels is justified. It should at least be at a level comparable with taxes for fuels used by trains and buses and I cannot see any reason for the industry to plead it needs special consideration.