Chasing tails due to Mouse tales ...

H2 has many uses, and the cost and emissions of production matter. You had a lovely example of where things worrked, with a large subsidy to start up. There's a difference, though, between ground vehicles that can carry the weight of the tanks easily and airplanes where weight is more of an issue. Not that it can't be done; somebody will succeed in doing it.

However, if it is as much a niche thing for planes as it is for ground vehicles it's unlikely to put a well-conceived, designed, and built HSR line out of business. Assessing CAHSR's compliance with those criteria is left as an exercise for the reader.