I agree there appear to be very good reasons not to use these.
Foling at 500kmph (edit: more like 250kmph by the looks of it) 10 metres above the water seems to just be inherently bonkers as a means of mass transportation given the very limited room for error/failure that results in everyone on board being instantly killed. Planes and helicopters can glide/autorotate, ships move slower.
The 3d mock ups and carefully shot video of the first flight (that obscures the fact it's a very small scale model prototype) suggest vapour ware scam startup.
Honestly for the love of god, can we just have trains?