Doesn’t account for the cost of helicopter landing platforms at every station, for one. Or the cost of building additional helicopters to meet current BART scale, or the cost of the number of accidents you’d have once it scaled, or the cost of having all transit halt whenever there’s an air incident, or literally anything about reality. Like, are you people being serious or just smirking about your spherical helicopters?

The error is completely ignoring the negative economic externalities of NOT having public transportation and the positive economic and environmental externalities of having public transportation.