Certification costs would be enormous
If they're planning on operating this vehicle from the US or many other countries, it'll have to be certified before it can carry passengers for hire. It costs millions to certify a basic private plane, and the more complex the plane, the higher the certification costs. Unless this vehicle is put into a special category that makes it exempt from most Federal Air Regulations (seems unlikely), it'll either have to find a less restrictive haven for operations or pay many million dollars for certification.