Theorycrafting is all well and good but if you claim that some metric X (farebox recovery) is negatively correlated with some outcome Y (frequent good transit) then you do have to explain why all the good outcome Ys actually have high X. Reality has to meet the theory.
Perhaps drivers/commuters should also be better charged for the resources they use:
* https://en.wikipedia.org/wiki/Congestion_pricing
* https://en.wikipedia.org/wiki/The_High_Cost_of_Free_Parking
* https://en.wikipedia.org/wiki/Carbon_price
We can let The Market™ decide what the alleged convenience of driving is worth.
I sudoect that airports can be far more portable than airlines, actually, since shopping, eating and drinking are much cheaper to deliver on the ground. And there’s parking too.
One might have instead believed that because SFO is so valuable to the region it should be heavily subsidized, but the property repeated worldwide is that valuable things are things people don't mind paying to use. Because they're valuable.