Gasoline is flammable and is used with little concern by drivers everywhere. Even the battery powered vehicles are not exempt from bursting into flames. I don't think flammability is an issue that should detract from the adoption of hydrogen.
I think the lack of hydrogen powered cars can be attributed to two factors:
- Lack of infrastructure
- Little market interest
Liquid fuels (gasoline, diesel, kerosene), and electricity have a nationwide/worldwide infrastructure working right now. Hydrogen filling stations may be available in some areas, but they are uncommon.
Who will buy the hydrogen cars? I'm all for research and development, but before production can begin, there needs to be customers. If a consumer were to decide between an electric, a hybrid, and a hydrogen powered vehicle, why would they choose hydrogen?
Driving distance? Environment? Price? Style? Status?
I don't see hydrogen taking the lead in any category.