I don't think I want to be strapped into that thing going down a very large hill. Looks like it would be easy to run over your own feet in it. It also seems that if it started tumbling that it could be very bad news for your head.
The single frame is taking a huge stress and showing a huge amount of flex and it it failed it would do so catastrophically and take your backbone with it while doing interesting things to your head.
The traditional diamond frame is taking much stress and failure is more likely to be progressive. At worst you would take a tumble rather than being guillotined.
Anyway a bike is the wrong comparison. It is a reverse scooter (frame on top instead of underneath). I can't see to what benefit.
As a method of execution I would prefer an electric chair ...