well if you're assuming the same number of passengers - given the logistics and hassles of air travel, one is likely more inclined to travel with hassle-free HSR, not to mention the secondary economic benefits
When investors look to invest, they want a fast ROI. Engineering company likes this typically takes many years to fruition or maybe not. It's much easier to justify dumping money on these "tech" companies like WeWork, AirBnb hoping to get another facebook unicorn than putting money into real engineering company like Makani.